Browse Topic: Water pumps

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Replacing Twin Electric Fan Radiator with Single Fan Radiator2019-28-238111/21/2019
Downsizing is one of the crucial activities being performed by every automotive engineering organization. The main aim is to reduce - Weight, CO2 emissions and achieve cost benefit. All this is done without any compromise on performance requirement or rather with optimization of system performance. This paper evaluate one such optimization, where-in radiator assembly with two electric fan is targeted for downsizing for small commercial vehicle application. The present two fan radiator is redesigned with thinner core and use of single fan motor assembly. The performance of the heat exchanger is tested for similar conditions back to back on vehicle and optimized to get the balanced benefit in terms of weight, cooling performance and importantly cost. This all is done without any modification in vehicle interface components except electrical connector for fan. The side members and brackets design is also simplified to achieve maximum weight reduction. Further Cooling system performance of engine is evaluated along with Fuel efficiency; results are compared with present configuration.
Bhargava, Aashish, Soni, Gaurav, Warkhade, Tushar
Glossary of Engine Cooling System TermsJ1004_201904 (Historical)4/22/2019
The objective of this glossary is to establish uniform definitions of parts and terminology for engine cooling systems. Components included are all those through which engine coolant is circulated: water pump, engine oil cooler, transmission and other coolant-oil coolers, charge air coolers, core engine, thermostat, radiator, external coolant tanks, and lines connecting them.
Cooling Systems Standards Committee
An Innovative Electric Motor Cooling System for Hybrid Vehicles - Model and Test2019-01-10764/2/2019
Enhanced electric motor performance in transportation vehicles can improve system reliability and durability over rigorous operating cycles. The design of innovative heat rejection strategies in electric motors can minimize cooling power consumption and associated noise generation while offering configuration flexibility. This study investigates an innovative electric motor cooling strategy through bench top thermal testing on an emulated electric motor. The system design includes passive (e.g., heat pipes) cooling as the primary heat rejection pathway with supplemental conventional cooling using a variable speed coolant pump and radiator fan(s). The integrated thermal structure, “cradle”, transfers heat from the motor shell towards an end plate for heat dissipation to the ambient surroundings or transmission to an external thermal bus to remote heat exchanger. A complete lumped parameter numerical modelling was implemented to estimate the thermal behavior of the corresponding electric motor cooling system. Experimental and numerical results compare the temperature, heat flux, and cooling power measurements. For 250VA thermal load applied, the hybrid heat rejection strategy could save up to 33% of the power consumption while the operating condition is secured. Higher thermal loads can be handled through the combined passive and active pathways with minimum power consumption. Based on these findings, integrated electric motor cooling merits attention for further investigation through field testing, scaling, and utilization in other applications.
Shoai Naini, Shervin, Huang, Junkui (Allen), Miller, Richard, Wagner, John R., Rizzo, Denise, Sebeck, Katherine, Shurin, Scott
Research on Constant Speed Control Strategy of Water Medium Retarders for Heavy-Duty Vehicles2019-01-13044/2/2019
Hydraulic retarders are extensively used in heavy-duty vehicles because of their advantages, such as their large braking torque and long continuous operating hours. They can reduce the vehicle velocity by converting the kinetic energy of a traveling vehicle to the thermal energy of the working fluid. The water medium retarder is a new type of hydraulic retarder with the characteristics of high power density and simple structure. It uses the engine's coolant as the working medium, and the heat is directly taken away by the vehicle cooling system. Therefore, the heavy-duty vehicle can achieve long-term continuous braking during the downhill process. One of the main functions of water medium retarder is driving downhill at a constant speed which determines whether the vehicle drives stably and safely. Therefore, studying the constant-speed control strategy during downhill driving is particularly important. In this paper, the structure and working principle of water medium retarder and the dynamic characteristic are analyzed. The dynamic models of vehicle and water medium retarder are established based on dynamic analysis during downhill process. The braking process that involves the water medium retarder is divided into three stages. Then the constant speed controller of water medium retarder which include three control algorithms is designed, respectively, PID algorithm, fuzzy algorithm and fuzzy-PID algorithm. The vehicle dynamic model and the constant speed control model of water medium retarder are established using MATLAB/SIMULINK. The simulation has been carried out and the comparative analysis of three algorithms mentioned above is conducted. The simulation results show that three controllers designed in this paper can quickly and accurately calculate the target filling ratio, fuzzy controller has better constant torque control performance, and the vehicle speed error is significantly reduced, which improves the stability of the vehicle during downhill process.
Lei, Yulong, Song, Pengxiang, Fu, Yao, Wang, Yuhai, Zhang, Yuchen
Application of Electrically Driven Coolant Pumps on a Heavy-Duty Diesel Engine2019-01-00741/15/2019
A reduction in CO2 emissions and consequently fuel consumption is essential in the context of future greenhouse gas limits. With respect to the thermodynamic loss analysis of an internal combustion engine, a gap between the net indicated thermal efficiency and the brake thermal efficiency is recognizable. This share is caused by friction losses, which are the focus of this research project. The parasitic loss reduction potential by replacing the mechanical water pump with an electric coolant pump is discussed in the course of this work. This is not a novel approach in light duty vehicles, whereas in commercial vehicles a rigid drive of all auxiliaries is standard. Taking into account an implementation of a 48-V power system in the short or medium term, an electrification of auxiliary components becomes feasible. The application of electric coolant pumps on an Euro VI certified 6-cylinder in-line heavy-duty diesel engine regarding fuel economy was thus performed. The engine has two cooling circuits, one low temperature circuit for the charge air coolers and one high temperature circuit as main circuit, which are split in two separate circuits. This layout provides the opportunity to determine the charge air temperature level on demand, which may on the one hand be used for lower NOx emissions, or on the other hand enable exhaust gas heating. Moreover, an operating strategy with respect to a reduced coolant flow rate is investigated and the advantages in the brake thermal efficiency are determined. Future emission tests will include real driving and cold-start phases also for heavy-duty application, where an optimized thermal management will play a key role. The influence of the modified cooling system layout on the warm-up in the worldwide heavy-duty transient cycle is thus presented. Furthermore, the additional degree of freedom offers the possibility to run the pump after the engine is turned off. This post-run phase and its benefits on component protection will also be presented.
Granitz, Christina, Ratzinger, Josef, Eichlseder, Helmut, Surace, Alfonso
Development of Horizontal Water Cooled Diesel Engine to Achieve High Power Density2018-32-006410/30/2018
The horizontal water cooled diesel engine has a structure including all component parts such as a fuel tank that are necessary to drive engine, and is often a single cylinder engine. It is mounted on many applications such as power tiller and water pump because of high general versatility of installing owing to belt drive. It has a simple structure because of single cylinder, and is active mainly in Southeast Asia. At the same time, the market requires this type of engine higher power while a compact structure is also required from the viewpoint of easy to supply and use. In other words, “High power density” that is improving the output per body size has been required. We have responded to the demand of “High power density” by increasing output without changing the engine size. In order to keep the engine size, we have been enlarging displacement by using our peculiar stroke-up expertise and original bore-up contrivance. In addition to those techniques, we introduced analytic technology for early approach to optimal solution. While we had used deep bowl combustion chamber for emphasizing medium and low speed torque, we adopted shallow dish combustion chamber because we shortened the compression height of piston for stroke-up. We utilized combustion analysis so as to approach optimal solution early because we have no base data of shallow dish combustion chamber. In addition, we used stress analysis to optimize the hardening of crankshaft. As written above, by incorporating analytic technology in addition to conventional development methods, we have been supplying correct size engines speedily in response to requirement of market. In this paper, we introduce the techniques that we adopted in order to realize the high power density.
Komai, Yoshinobu, Takashima, Yusuke, Fujiwara, Tsukasa, Okamoto, Hisao, Kawahara, Minoru
Energy Consumption Test and Analysis Methodology for Heavy-Duty Vehicle Engine Accessories03-11-05-003610/3/2018
Fuel economy is a crucial parameter in long-haulage heavy-duty vehicles. Researchers tended to focus initially on engine combustion efficiency, while modern researchers turn their attention to the energy consumption of engine accessories in an attempt to enhance fuel economy. The accessories investigated in this study include the cooling fan, water pump, air compressor, power steering pump, air-conditioning (AC) compressor, and generator. Normally, accessory energy consumption analysis is based on rig data and simulation results. Here, we focus on the disparate test environments between the rig and vehicle to establish a novel constant power test method; the proposed method provides accurate accessory power data under different working conditions. A typical highway driving cycle is selected to collect accessory duty-cycle. The heavy-duty vehicle accessories’ energy consumption distribution under highway road conditions is obtained through the repeated road tests. Accessories comprise energy consumption proportions of 4.7%-6.4% of the engine in winter and 10.3%-12.6% in summer; they show different characteristics under different temperature or road conditions. The two influence factors of accessory energy consumption, constant power and duty-cycle, are analyzed to evaluate possible energy-saving schemes. Applying the clutch or electrical accessories, especially for the cooling fan and air compressor, is recommended.
Zhong, Liang
Development of a Compact and High-Performance Radiator for Thermal Management of Environmentally-Friendly Cars2018-01-00874/3/2018
To comply with increasing fuel efficiency regulations, a low temperature radiator (LT radiator) is required to cool the charge-air system of a turbocharged engine. These engines are important to use for environmentally-friendly cars. Since heavy-duty and high-performance cars demand high cooling performance, the main radiator alone is typically insufficient in meeting the vehicle’s cooling requirements. An additional radiator installed in the front of the wheel-well is required to meet the extra cooling demand. In order to install this radiator in the front of the wheel-well, guaranteed performance in the limited packaging space and impact resistance of the leading tube edge are required. We developed the Supplementary Inner-Fin Radiator (SIR) which achieves the compact, high-performance, and durability requirements by use of an inner-fin tube (I/F tube). The purpose of this paper is to report our design approach and product specifications of the SIR. In particular, the impact resistance requirement is set from understanding the vehicle usage environment. This is an important consideration due to coolant leaks caused by damaged radiator tubes. First, we estimated the impact energy of 0.42 J from modeling a stone-impact environment with the conditions of a 7.7 mm sized stone and a vehicle speed of 130 km/h. The tube resistance target of 0.63 J was set in consideration of a safety factor. Second, we discovered that the stone hits the tube from the front-side when the radiator is placed in the front of the wheel-well, and so we analyzed the inner-fin tube from the viewpoints of shock absorption and deformation suppression. Finally, we confirmed that the SIR achieves this target of tube impact resistance (0.78 J > 0.63 J) by means of an impact bench test.
Akagi, Shota, Ninagawa, Toshihide
A Review of the State of the Art of Electric Traction Motors Cooling Techniques2018-01-00574/3/2018
This paper provides a review on state-of-art modern cooling systems employed for thermal cooling of electric motors for vehicle applications. In recent years, the pursue of a more sustainable and ecofriendly mobility has pushed the research towards the development of electric vehicle powertrain systems. Besides the evident advantages of the adoption of electric traction systems in terms of pollution and efficiency, the need of an effective cooling system for the electric machine components gained more and more importance in order to maintain high efficiency and ensure high durability. In fact, it is known that high temperatures can be harmful for the electric motor: besides the evident damages for mechanical parts, the influence on the permanent magnet properties is not negligible [1] [2]. In this fast-evolving environment, different solutions for the thermal problem have been researched and adopted, each one with its own pros and cons. Those who face the development of a PM machine can found plenty of these solutions in literature; so, the purpose of this paper is to draw a first qualitative comparison among the most important mechanisms available to extract heat from the electric machine and to guide the reader to an efficient and effective solution. Various methodologies for heat extraction are here described: resilient thermal pads for a conductive cooling; forced air and liquid loops, spray cooling and hollow rotor shaft for gases/fluids convective cooling methods. Finally, it is provided a table for a qualitative comparison among the various cases.
Carriero, Alberto, Locatelli, Matteo, Ramakrishnan, Kesavan, Mastinu, Gianpiero, Gobbi, Massimiliano
Design and Development of Cooling System for a Formula SAE Race Car2018-01-00794/3/2018
In Formula Student, the vehicle working parameters are quite disparate from that of a commercially designed vehicle. The inability of teams to incorporate the atypical running conditions in their design causes multiple unforeseen issues. One such condition where the teams fail to improvise upon is the cooling system. Due to the high performance requirement of the competition, multiple teams participating face recurring heating problems. Maximum efficiency from a combustion vehicle can only be achieved when the cooling system is designed to handle the increasing power demand. This paper brings forth a detailed study on the intricate design of the cooling system. The problem has been approached using both theoretical and simulation models. Firstly, NTU-ℇ method was used to calculate the overall heat transfer coefficient and the temperature drop through the radiator core. Various parameters like core size, mass flow rate of water and air, fan configurations etc., were taken into consideration. Star CCM+ software was used to perform full body analysis to study the positioning of the radiator on the race car. Following this, the theoretical calculations were validated by performing thermal analysis on the same software. The results obtained from these models were validated experimentally on the vehicle using data acquisition. Temperature sensors placed at inlet and outlet of the radiator were used to record the data. The study not only resulted in designing an efficient cooling system but also laying out a systematic approach for further development.
Bahuguna, Rishabh, Prasad, Tanmay, Khanna, Rishabh, Kumar, Akshyt Bimal, gopal, K Nantha, Srivastava, Sushant, Mishra, Aagosh, B, Ashok
Simulation-Driven Approach to Design & Evaluate Vehicle Thermal Management2018-01-11834/3/2018
In today’s automobile industries to improve the fuel economy lots of weight reduced in all the systems of the vehicle, particularly in the engine cooling system. Due to the lighter weight engine cooling systems, the vehicles might face many temperature challenges and sustainability issues. The automotive cooling system has unrealized potential to improve internal combustion engine performance through enhanced coolant temperature control and reduced parasitic losses. The idea of this work is to validate the downsized heat exchanger to use in an optimal engine cooling module without compromising the functional requirements. For this study a plug-in hybrid electric vehicle (PHEV) engine internal cooling system is modelled in GT-SUITE®. The PHEV cooling network comprises of high temperature (HT) loop, low temperature loop (LT) loop and the battery loop. Flow networks converted and imported from GEM3D® and advanced features available for fast modelling is used for developing the complex 1D engine cooling system in GT-SUITE®.1D tool KULI® is used for optimizing and validating the design proposal. Transient simulation is performed for an extreme ambient thermal test cycle. The coolant flow rates across the heat exchanger, other cooling system components and the temperature profile across the engine is measured and correlated with the vehicle test results. The results obtained from the proposed design correlates well with the test results. This methodology provides a pre-developed cooling module design at the early stage of product development. Overall it also ensures a system level technical cost reduction.
Arthanari, Tharunnarayanan, S, Sathish Kumar
Parallel Thermal Management System of the Water Medium Retarder2018-01-07774/3/2018
The thermal management system of the water medium retarder using engine coolant (water and ethylene glycol) as transmission medium, omits oil-water heat exchanger in the structure. When the hydraulic retarder is operated, the valve is connected with the retarder and water pump, and then the engine coolant enters the working chamber. The kinetic energy of the vehicle is converted into internal energy of the coolant, and the heat is discharged to the external environment through the engine thermal management system. The braking torque of the water medium hydraulic retarder is determined by the water medium flow rate in the working chamber. The smaller the valve opening degree, the greater the braking torque and the faster the heating transmission fluid. Small valve opening is not conducive to the loss of heat. It will affect the normal working of the engine and hydraulic retarder. In this paper, the thermal management system of the water medium hydraulic retarder is independent of the engine. Hydraulic retarder can be controlled individually so that to improve the auxiliary braking performance. Firstly, the independent thermal management system is designed according to the heat dissipation requirement of the hydraulic retarder. Secondly, the heat transfer of the hydraulic retarder thermal management system is analyzed. Finally, compare to the thermal management system of the traditional water medium retarder and the paper. The results show that the thermal management system of parallel water medium hydraulic retarder can effectively use the radiator cooling capacity, and reduce the working temperature of the water hydraulic retarder.
Gao, Xin, Lei, Yulong, Chen, Wei, Cui, Guokai, Zhong, Lei
Automotive Water Pump Methodology using Head Pump and Rotor Power for Correlations2017-36-039811/7/2017
Aiming the decrease of manufacturing costs, the automotive industry uses Computational Aided Engineering (CAE) and prototype testing for product development. In the field of simulation CAE could be performed using FEA (finite element analysis) or CFD (Computational Fluid Dynamic), the last one is the analysis of systems involving fluid flow, heat transfer and associated phenomena such as chemical reactions by means of computer-based simulation. One of the most important components of cooling system is a water pump which is evaluated through the fluid dynamic analysis. Therefore, this work aims to analyze the fluid flow inside an automotive water pump considering a three-dimensional steady-state using CFD, but also developing a methodology to evaluate it. The parameters of the analysis and the volumetric mesh were according to the simulated results approached the experimental results. After correlating the simulation with the physical test, other simulations were carried out, using the same methodology, but changing the volumetric flow rates and rotor rotations. With this work, it was possible to construct the characteristic curve of the pump in study, as well as calculating the head pump and its efficiency and become possible the application for new development of water pumps.
de Oliveira e Caldeira, Luiz Guilherme, Pockszevnicki, Bruno Cesar, de Assis, Geisiel Moreira, Magalhães, Daniella Fernanda dos Santos
Analysis of a Heat Exchanger for the Cooling Systems of a Vehicular Prototype2017-36-034711/7/2017
This work aims to study the selection of a heat exchanger available in the market with the objective of implementing it in a vehicle. The vehicle used for the tests was a prototype, developed by Formula UFMG team. It was made an experimental and a theoretical study in order to calculate the power of the CB600F engine to compare with the experimental study of heat dissipation of the selected heat exchanger. This comparison was made to check whether the heat exchanger reaches the vehicle’s requirements, and it has shown good convergence. The engine technical features were used in the theoretical studies, and thus the power was calculated. The experimental data were obtained by assembling the car in a roller dynamometer with the necessary instrumentation for these tests being performed. In these tests, the critical operation conditions of the vehicle were simulated, once the engine operates at a temperature of 95°C. For the experimental calculation of the dissipated heat by the radiator, experiments were carried out to obtain the water pump flow curve and the difference of the water inlet and outlet temperatures in the heat exchanger. It was concluded in the present work that this heat exchanger obtained satisfactory performance in the tests, proving that the radiator was correctly selected, since the vehicle was subjected to extreme conditions of use and did not overheat.
de Lima, Bruno Silva, de Oliveira, Rafael Megale, de Oliveira Moraes, Luiz Fernando, Araújo, Gustavo Abreu, de Almeida Carvalho, Gabriel Mendes
International develops new, lighter A26 engine to replace N1317TOFHP04_104/1/2017
Any time a new engine is announced, it is major news. Pairing a new engine with a new approach to engine development is even bigger news. International Truck recently unveiled its all-new engine for the Class 8 market: the International A26. Along with that came news of an initiative called Project Alpha, which brought together a small team of powertrain engineers dedicated to a new perspective on engine development. “The A26 was designed from the ground up to deliver industry-leading uptime, durability and reliability,” said Darren Gosbee, vice president of advanced engineering. The 12.4-L A26 sources a MAN D26 inline 6-cylinder crankcase from their partnership with the Volkswagen Group and surrounds it with numerous all-new components to optimize four key criteria: uptime, fuel efficiency, weight and NVH (noise, vibration and harshness).
Borst, Matthew
Calibration and Demonstration of Vehicle Powertrain Thermal Management Using Model Predictive Control2017-01-01303/28/2017
Control of vehicle powertrain thermal management systems is becoming more challenging as the number of components is growing, and as a result, advanced control methods are being investigated. Model predictive control (MPC) is particularly interesting in this application because it provides a suitable framework to manage actuator and temperature constraints, and can potentially leverage preview information if available in the future. In previous SAE publications (2015-01-0336 and 2016-01-0215), a robust MPC control formulation was proposed, and both simulation and powertrain thermal lab test results were provided. In this work, we discuss the controller deployment in a vehicle; where controller validation is done through road driving and on a wind tunnel chassis dynamometer. This paper discusses challenges of linear MPC implementation related to nonlinearities in this over-actuated thermal system. Specifically, the fan and grill shutter actuators have a nonlinear influence on the individual airflows through the charge air cooler and radiator heat exchangers, and the design choices in dealing with these nonlinearities affects the control performance and controller memory requirements. The memory requirements of the resulting controller are also analyzed and compared to other MPC controllers.
Bonkoski, Phillip, Karnik, Amey Y., Fuxman, Adrian
The New Toyota Inline 4-Cylinder 2.5L Gasoline Engine2017-01-10213/28/2017
In order to adapt to energy security and the changes of global-scale environment, further improvement of fuel economy and adaptation to each country’s severer exhaust gas emission regulation are required in an automotive engine. To achieve higher power performance with lower fuel consumption, the engine’s basic internal design such as an engine block and cylinder head were changed and the combustion speed was dramatically increased. Consequently, stroke-bore ratio and valve layout were optimized. Also, both flow coefficient and intake tumble ratio port were improved by adopting a laser cladded valve seat. In addition, several new technologies were adopted. The Atkinson cycle using a new Electrical VVT (Variable Valve Timing) and new combustion technology adopting new multi-hole type Direct fuel Injector (DI) improved engine power and fuel economy and reduced exhaust emissions. Variable cooling system with an electric water pump and Flow Shut Valve (FSV) improved fuel economy by reducing warm-up time and mechanical losses. Also, a newly developed variable oil pump has significantly reduced friction losses. By implementing these new technologies, the new naturally aspirated 2.5L gasoline engine achieved over 40% thermal efficiency and over 150kW engine power. In combination with a new 8 speed Automatic Transmission, fuel consumption was reduced by over 16%.
hakariya, Masashi, Toda, Tadashi, Sakai, Mitsuto
Optimization of a Military Ground Vehicle Engine Cooling System Heat Exchanger - Modeling and Size Scaling2017-01-02593/28/2017
Heat rejection in ground vehicle propulsion systems remains a challenge given variations in powertrain configurations, driving cycles, and ambient conditions as well as space constraints and available power budgets. An optimization strategy is proposed for engine radiator geometry size scaling to minimize the cooling system power consumption while satisfying both the heat removal rate requirement and the radiator dimension size limitation. A finite difference method (FDM) based on a heat exchanger model is introduced and utilized in the optimization design. The optimization technique searches for the best radiator core dimension solution over the design space, subject to different constraints. To validate the proposed heat exchanger model and optimization algorithm, a heavy duty military truck engine cooling system is investigated. For a convoy escort driving cycle, numerical results demonstrate that by increasing the prototype radiator frontal area, the cooling system energy cost can be significantly reduced. The proposed radiator size scaling algorithm offered a methodology of evaluating the tradeoff between physical dimension, heat generation and power. It is a powerful tool that allows optimal deciding the space, cooling and power usage for a given cooling system application.
Tao, Xinran, Wagner, John R.
Comparison of Extended Life Coolant Corrosion Protection Performance2017-01-06273/28/2017
In this paper, new test results in the use of electrochemical techniques to measure corrosion in extended life engine coolants are presented. Corrosion protection performance of the engine coolants (including both fresh coolants and simulated used coolants) for typical cooling system metals under heat rejecting and heat accepting surface corrosion conditions for both general corrosion and localized corrosion are measured under conditions similar to the ones encountered in vehicle engine cooling systems as a function of immersion time. Fleet tests of the coolants were also conducted. They are used to provide support on the electrochemical test methodologies adopted. The effective use of electrochemical techniques to aid the development of the next generation of extended life coolant technologies with improved corrosion protection performance and a longer service life will be demonstrated and discussed.
Yang, Bo, Woyciesjes, Peter, Gershun, Aleksei
Optimization of Active Grille Shutters Operation for Improved Fuel Economy2017-01-15133/28/2017
The airflow into the engine bay of a passenger car is used for cooling down essential components of the vehicle, such as powertrain, air-conditioning compressor, intake charge air, batteries, and brake systems, before it returns back to the external flow. When the intake ram pressure becomes high enough to supply surplus cooling air flow, this flow can be actively regulated by using arrays of grille shutters, namely active grille shutters (AGS), in order to reduce the drag penalty due to excessive cooling. In this study, the operation of AGS for a generic SUV-type model vehicle is optimized for improved fuel economy on a highway drive cycle (part of SFTP-US06) by using surrogate models. Both vehicle aerodynamic power consumption and under-hood cooling performance are assessed by using PowerFLOW, a high-fidelity flow solver that is fully coupled with powertrain heat exchanger models. The fuel economy calculation is based on a quasi-static drive cycle simulation where the engine power is calculated to match drive cycle loads from aerodynamic forces, translational and rotational inertia, rolling resistance, transmission and tire slip losses, and auxiliary parts. The engine heat rejection is calculated from these same loads. The operation of AGS opening is determined by minimizing instantaneous vehicle aerodynamic power constrained by the radiator heat rejection requirement. The improved fuel economy of actively controlled AGS is then compared to the cases with fully open and scheduled operations. The approach in this study provides an effective framework for the design of fuel-efficient vehicles in earlier design stages.
Cho, Young-Chang, Chang, Chin-Wei, Shestopalov, Andrea, Tate, Edward
E-KERS Energy Management Crucial to Improved Fuel Economy2016-01-19479/18/2016
The operation of a conventional passenger car is characterised by increasing or maintaining the kinetic energy, when accelerating or cruising the vehicle, and reducing the kinetic energy by using the brakes. While the energy taken by the friction brakes to slow the vehicle is dissipated into heat, the introduction of Kinetic Energy Recovery Systems (KERS) has permitted the recovery of part of the braking energy. This reduces the amount of energy needed from the internal combustion engine (ICE). The contribution reviews the latest developments in electric KERS (E-KERS), with emphasis to round trip efficiency wheels to wheels and electrification of the powertrain. The contribution considers the opportunity to connect the E-KERS traction battery to other electric machines, such as an electrically assisted turbocharger (E-TC) connected to a motor/generator unit, or an electric water pump (EWP), to further optimise the vehicle operation. The electrically assisted TC permits a reduced turbo-lag and the recovery of the extra energy at the TC turbine. The EWP permits to reduce the inertia of the cooling system precisely operated for a faster warm-up and better steady state conditions. The vehicle energy management permitted by the E-KERS and the electrification is concluded to represent a fundamental step to improve the fuel economy of today’s passenger cars.
Boretti, Albert, Al-Zubaidy, Sarim
Reception Plate: a Comparative Test Bench of Structure-Borne Noise Sources2016-01-17986/15/2016
The goal of the present study is to provide a simple method to compare structure borne noise sources in order to choose the most efficient one, considering the transmission of dynamic forces. It is well known that mechanical sources are not only dependent of the source itself but also of the receiving structure, in addition real sources cannot be reduced to a transverse force acting on the structure but more complicated effect like moment excitation must be taken into account. The advantage of the reception plate method is to characterize the source globally by the level of vibration of the reception plate whatever the type of excitation, the idea is basically to characterize mechanical sources as it is done for acoustical sources in reverberant rooms. A reception plate test bench has been developed to determine the power injected by mechanical sources. Two prototype plates have been designed in order to have different receiving mobilities. The reception plates have been characterized through their damping factors, modal overlaps, and diffusivity of the vibration fields measured by Laser Doppler Vibrometer (LDV). The goal is to perform a statistic analysis to evaluate the influence of number and position of sensors on the averaged velocity values over the reception plate on the accuracy of the measurements. This quantity allows to estimate the injected power into the receiving structure. A shaker (broadband excitation) and a small pump used in automotive industry (tonal excitation) have been characterized by the test bench. Comparison of injected power allows us to rank source efficiencies.
Buisson, Quentin, Guyader, Jean-Louis, Puvilland, Serge, Carniel, Xavier, Soenen, Maximilien
Small-Volume Pressurized Sample Handling SystemTBMG-248416/1/2016
A method was developed for effective, efficient, non-destructive, in-situ sample processing. Pressure vessels are used for sample delivery and collection, a shaker is used to keep the particles suspended, a back pressure of argon gas is used to keep the system under pressure to regulate the flow, and flow restrictors and frits are used that never come into contact with the sample slurry to avoid clogs.
Modeling and Analyzing for Hydraulic-Driven Cooling System of Heavy Duty Truck2016-01-02224/5/2016
The heavy duty trucks have large engine power and drive continuously in mountainous area, so the heat dissipation of engine is very important. In the traditional cooling system with fixed transmission ratio fan, the cooling capacity is insufficient and the engine is easy to be over-heated when the engine is working in low speed and heavy load conditions. Owning to the bigger size of electric motor compared to the hydraulic motor, it is not suitably applied to the heavy duty trucks. Contrasted with the electric motor, the hydraulic drive cooling system is widely applied in heavy duty trucks due to smaller size, larger power, continuous speed modulation and flexible installation location. However, the low transmission efficiency of the pump-motor system results in high power consumption of the cooling system. In this paper, the mathematical and simulation model of hydraulic-driven fan cooling system is established for the specific engine. The study applies the digital PID controller of continuous system to control the fan. The control algorithm of anti-integral saturation is compared with the conventional method. The results show that during the time progress of 700s, the mean power consumption with anti-integral algorithm respectively reduce by an average of 40.8%, 35.1% and 29.2% in the target temperature of 363.15K, 364.15K, and 365.15K compared with the traditional control method. Moreover, the PID control with anti-integral algorithm can improve the temperature control accuracy and effectively avoid the excessive cooling.
Zhang, Xingyu, Yang, Bo, Tan, Gangfeng, Mei, Binyu, Li, Zhilei, Yang, Zhongjie, Wang, Can
A DFSS Approach to Design Cooling System of Small Passenger Car Having Rear Engine and Front Mounted Radiator2016-01-06574/5/2016
DFSS is a disciplined problem prevention approach which helps in achieving the most optimum design solution and provides improved and cost effective quality products. This paper presents the implementation of DFSS method to design a distinctive cooling system where engine is mounted in the rear and radiator is mounted in the front of the car. In automobile design, a rear-engine design layout places the engine at the rear of the vehicle. This layout is mainly found in small, entry level cars and light commercial vehicles chosen for three reasons - packaging, traction, and ease of manufacturing. In conventional Passenger cars, a radiator is located close to the engine for simple packaging and efficient thermal management. This paper is about designing a distinctive cooling system of a car having rear mounted engine and front mounted radiator. This kind of arrangement requires lengthy coolant lines extended between the radiator and the engine throughout the length of the car, routed beneath the car. The U-shaped arrangement where radiator and engine are at higher coolant head and cooling lines are at very low coolant head becomes critical as air traps in the coolant system during coolant filling and de-aeration process. This restricts the coolant circulation during vehicle running-in and thus affect the life of critical components due to overheating. This paper also explains cooling system having external bypass instead of internal bypass to reduce overall cost and to provide simple and compact engine bypass circuit. The external bypass close to coolant pump offers a much lower resistance flow path as compared to the long radiator cooling lines increasing the risk of less coolant flows through the radiator as compared to bypass. These challenges were addressed using DFSS and DOE method. An optimum Design is finalized using DFSS approach and based on the analysis of the various tests carried out as per DOE. This design provide compact packaging of coolant system, ensure better thermal management and maintain good aesthetics of the automobile. The serviceability of the engine i.e. filling of the coolant and process of de-aeration is also simplified with the finalized design.
Sethuramalingam, T, Parmar, Chandrakant, Tiwari, Sashikant
Influence of Advanced Technology for Thermal Management on SUV2016-01-02384/5/2016
Reducing fuel consumption is a major challenge for vehicle, especially for SUV. Cooling loss is about 30% in total energy loss under NEDC (New European Driving Cycle) cycle. It is necessary to optimize vehicle thermal management system to improve fuel economy. Otherwise, rapid warm-up is beneficial for friction reduction and passenger comfort in cold-start. Vehicle thermal behavior is influenced by cooling system layout, new technology and control strategy. Thermal management simulation is effective to show the energy flow and fuel consumption under the influence of new technology under NEDC cycle. So 1D thermal management simulation model is created, including vehicle, cooling system, lubrication system and detailed engine model with all friction components. And the interrelations between all the components are considered in the model. For model calibration, large amount of data is obtained from vehicle tests such as transient fuel consumption and transient coolant temperature. Base on the accurate model, electric water pump, split cooling, controlled oil pump and other technology are applied to show the influence of fuel consumption and warm-up behavior during drive cycles of NEDC under 20°C and -20°C ambient temperature. And all the modifications are verified for reliability under the worst cycle. And the most effective technology will be applied for new generation engine of GWM (Great Wall Motor company Limited).
Liu, Gang, Zhao, Zheng, Guan, Hao, Liu, Yaqi, Zhang, Chunhui, Gao, Dingwei, Zhou, Wuming, Knauf, Juergen
An Engine Thermal Management System Design for Military Ground Vehicle - Simultaneous Fan, Pump and Valve Control2016-01-03104/5/2016
The pursuit of greater fuel economy in internal combustion engines requires the optimization of all subsystems including thermal management. The reduction of cooling power required by the electromechanical coolant pump, radiator fan(s), and thermal valve demands real time control strategies. To maintain the engine temperature within prescribed limits for different operating conditions, the continual estimation of the heat removal needs and the synergistic operation of the cooling system components must be accomplished. The reductions in thermal management power consumption can be achieved by avoiding unnecessary overcooling efforts which are often accommodated by extreme thermostat valve positions. In this paper, an optimal nonlinear controller for a military M-ATV engine cooling system will be presented. The prescribed engine coolant temperature will be tracked while minimizing the pump, fan(s), and valve power usage. A case study investigates the proposed control strategy’s performance in comparison to other methods for temperature tracking and energy conservation. The optimal nonlinear controller offered satisfactory coolant temperature tracking with an average error of 0.35°C and at least 13% reduction in total cooling power.
Tao, Xinran, Wagner, John R.
Model Based Design and Optimization of Vehicle Thermal Management System2016-01-02834/5/2016
More stringent federal emission regulations and fuel economy requirements have driven the automotive industry toward more sophisticated vehicle thermal management systems in order to best utilize the waste heat and minimize overall power consumption. With all new technologies and requirements, how to properly design, optimize, and control the vehicle thermal and cooling systems become great challenges to automotive engineers. Model based approach has become essential to the new thermal management system architectures design and evaluation of the optimal system solutions. This paper will discuss how the model based vehicle thermal system simulation tools have been developed from analytical & empirical data, and have been used for assessment and development of new thermal management system architectures.
Saha, Joydip, Chen, Harry, Rahman, Sadek
Cooling System Optimisation of a Multi - Point Fuel Injection Engine2016-28-00852/1/2016
In Conventional internal combustion engine cooling system, the coolant pump is belt-driven by the engine crankshaft. The direct coupling between engine and cooling pump results in an excessive flow of cooling fluid at part-load conditions and waste of energy in running the pump at engine cold start, which affects the engine efficiency and, as a consequence, the global fuel consumption. A study has been conducted on a Maruti 800cc MPFI engine cooling system in order to find a way to reduce common overheating problems at idle conditions and intermediate engine speeds with restricted airflow. The study involves testing of an engine radiator in a wind tunnel (calorimeter) to simulate the actual driving conditions. The coolant flow rate, pressure, and temperature characteristics were monitored at different positions in the cooling system while engine speed and load was varied. Engine performance test were carried out for different radiator ram air speeds. The results show that by adjusting the flow rates according to certain variables, the overall effectiveness of the cooling system can be increased and hence overheating problems can be minimized. A solution is proposed for improving the cooling system by employing an epicyclic gear train to vary the speeds thereby to vary the coolant flow rates in accordance to the coolant temperature.
Vadivelu, M A, Kumar, C Ramesh, Naiju, C D
Vibration Reduction of Single Cylinder Diesel Engine used for Agricultural Water Pumping2015-01-22916/15/2015
There are many environmental issues in India. Air pollution, water pollution, garbage, vibration, noise pollution and pollution of the natural environment are all challenges for India. India has a long way to go to reach environmental quality similar to those enjoyed in developed economies. Pollution remains a major challenge and opportunity for India. The review of trends in farm practices and machinery development suggests that vibration & noise problems are still prevalent in agricultural situations, even though there has been a steady increase in the availability of materials and equipment for vibration & noise control over recent years. Diesel engine is the main source of power for agricultural equipments, such as water pump set, compressor, electric generator and tractor. Even it is one of the sources of vibration & noise in agricultural field. There is reluctance of the agricultural sector to use of vibration & noise control methods. It is difficult to estimate the number of workers (self-employed and employees) in agriculture and forestry who suffer in India. In this project work, the challenge was to predict vibration performance / characteristics of 8 HP, 2100 rpm, single cylinder diesel engine. Also check the effect of up-gradation of same engine to 2600 rpm; which will be done to get more water quantity and at higher level /head. Engine model building was started with 3D CAD modeling using Pro/E software then discritization (Meshing) and Nastran solver deck / model with loads and boundary conditions was developed using Hyper Mesh software. Engine loads was calculated using analytical methods for 2100 rpm & 2600 rpm. Those excitation loads was used to simulate NVH behavior of engine using CAE method. Detailed vibration source identification was carried out by actual vibration measurement using B & K measuring system and NVH CAE simulation methods. Fuel tank and gear cover was potential candidate of vibration. Based on vibration source identification by both methods, design modifications were done and verified using NVHCAE simulation technique for 2100 rpm and 2600 rpm before final recommendation for design changes. Those modifications were showing good amount of vibration reduction for the respective natural frequencies as design changes were strengthening the plane surfaces of sheet metal fuel tank and gear cover. Design modifications were recommended to implement after prototype testing.
Jadhav, Pandurang Maruti, Dunung, Sandesh A, Nitnaware, Pravin T
Single Layer Cooling Module for A-B Segment Vehicles2015-01-16924/14/2015
Automotive world is rapidly changing driven by the CO2 emission regulations [1], [2] worldwide asking for a dramatic fuel consumption reduction. The on board thermal management has a relevant role influencing the front vehicle design and sizing to assure the right heat rejection capacity and being crucial to guarantee the on board system efficiency and reliability. In this context the dual level cooling system with water cooled charge air cooling is a clear trend leading to a new generation of systems [3, 4]. This paper describes a compact solution to effectively implement a dual cooling loop system with water cooled charge air cooler and water cooled condenser on small/subcompact cars giving the opportunity to integrate additional modules (e.g. in case of hybrid powertrain) to the secondary loop. The system key element is the capacity to manage the whole vehicle heat rejection need with a single layer radiator enabling the redesign of the front end so reducing the aerodynamic drag and making more effective the adoption of active aerodynamics devices (e.g. Active Grid Shutters). The proposed solution ensures all the advantages of water cooled charge air cooler enabling a further improvement of the air conditioning system thanks to a more effective condensation phase that also leads to noise reduction and lower fuel consumption in real world. The single layer cooling module has been developed in order to maximize the layout advantages of such a system, integrating on the same radiator both the high and low temperature cooling circuits enabling packaging an weight optimization at vehicle level. A Fiat 500 0.9L TwinAir 85 HP turbocharged engine vehicle demonstrator has been realized and fully tested. The system enables to reduce the thermal module thickness of 50 mm guaranteeing the demanded heat rejection and the fuel economy improvement (i.e. −5% on US06 @35°C). Further improvement can be achieved properly designed the vehicle front end.
Ferraris, Walter, Di Sciullo, Fausto, Malvicino, Carloandrea, Vestrelli, Francesco, Beltramelli, Fabrizio, Gotta, Giancarlo
Development of the Waste Heat Management System2015-01-16054/14/2015
Electric powered vehicles rely on electric heater to heat the cabin of the vehicle. These heaters consume electric energy from the battery and cause depletion of the vehicle's range by 20∼40%. In order to extend the range of electric vehicles, we need to increase the efficiency of HVAC. EV has waste heat but the heat power is much lesser than internal combustion engine and heat source is separated physically. In order to utilize waste heat to achieve better efficiency, heat collection, heat insulation, pre-heating are necessary. Based on the new concept system, we examined the effects of fuel efficiency
Park, Hee Sang
A 1D Method for Transient Simulations of Cooling Systems with Non-Uniform Temperature and Flow Boundaries Extracted from a 3D CFD Solution2015-01-03374/14/2015
The current work investigates a method in 1D modeling of cooling systems including discretized cooling package with non-uniform boundary conditions. In a stacked cooling package the heat transfer through each heat exchanger depends on the mass flows and temperature fields. These are a result of complex three-dimensional phenomena, which take place in the under-hood and are highly non-uniform. A typical approach in 1D simulations is to assume these to be uniform, which reduces the authenticity of the simulation and calls for additional calibrations, normally done with input from test measurements. The presented work employs 3D CFD simulations of complete vehicle in STAR-CCM+ to perform a comprehensive study of mass-flow and thermal distribution over the inlet of the cooling package of a Volvo FM commercial vehicle in several steady-state operating points. The results from these are correlated with test readings and are imposed on a 1D model of the cooling stack with inlet discretization, which features non-uniform boundary conditions. The 1D model is tested in steady state and transient conditions. Results are correlated with readings from dynamometer tests. No major indications were present to support that the non-uniform approach improves accuracy of simulation. Nevertheless, the results show, that the suggested predictive method successfully captures the thermal effects of recirculation while reducing the necessity for calibrations done by prototype testing.
Minovski, Blago B., Lofdahl, Lennart, Gullberg, Peter
Model Predictive Control for Engine Powertrain Thermal Management Applications2015-01-03364/14/2015
Numerous studies describe the fuel consumption benefits of changing the powertrain temperature based on vehicle operating conditions. Actuators such as electric water pumps and active thermostats now provide more flexibility to change powertrain operating temperature than traditional mechanical-only systems did. Various control strategies have been proposed for powertrain temperature set-point regulation. A characteristic of powertrain thermal management systems is that the operating conditions (speed, load etc) change continuously to meet the driver demand and in most cases, the optimal conditions lie on the edge of the constraint envelope. Control strategies for set-point regulation which rely purely on feedback for disturbance rejection, without knowledge of future disturbances, might not provide the full fuel consumption benefits due to the slow thermal inertia of the system. A solution to this problem is to design a control strategy that utilizes an estimate of variability of future disturbances. In this work, we consider the design of a controller for direct optimization of fuel consumption which allows for improved handling of constraints on temperatures and actuators. We propose a robust Model Predictive Control (MPC) formulation to optimize fuel consumption. The controller formulation guarantees that temperature constraints are met for future load and speed profile within specified bounds. The performance of the proposed controller is demonstrated through simulations on a system that uses an electric water pump, active thermostat and radiator fan, to control engine oil and metal (lumped block/head mass) temperature during regular driving so that fuel consumption is minimized.
Karnik, Amey, Pachner, Daniel, Fuxman, Adrian M., Germann, David, Jankovic, Mrdjan, House, Christopher
Application of Near-field Acoustic Holography to Low Temperature Engine Start-up Noise Issue Resolution2015-01-16664/14/2015
An issue of engine squealing in low temperature range (around −25°C) right after start-up emerged for a significant number of vehicles in a vehicle program. The earlier effort had focused on typical common culprits such as the pulley-belt systems etc. However, much effort, by subjective listening and guestimating hardware replacement, yielded no fruitful results for more than a year. The application of near-field acoustic holography on top of the engine in a climate chamber quickly identified several noise source locations. Further noise source identification effort on top, front and left side of the engine pinpointed the top three noise source locations: the idler pulley and water pump on front, the air compressor on right side, and the air intake throttle on top. Then a series of experiments were subsequently conducted, leading to a conclusion that the idler pulley was the source of the issue. Finally, investigation of the pulley system confirmed that the insufficient lubricating capacity at low temperature was the root cause. By switching to a type of lower base oil viscosity lubricating grease characterized by lower rotation torque in cold temperature conditions, the issue was successfully resolved.
Li, Lingzhi, Yang, Yimin, Zhao, Fengjun, Zhang, Zhi, Cheng, Hailong, Hou, Hangsheng
Electronic Design of Compact BLDC Motor Control2015-01-01334/14/2015
As many automotive functions evolve from purely mechanical to electrically-driven, the use of efficient brushless DC motors is becoming prevalent. This paper discusses the design of a BLDC motor controller, including the technical tradeoffs, hardware implementation, and testing results. This design example examines the specific requirements for a compact solution for driving a water pump, but the design methodology and tradeoffs also apply to other motor control applications where efficient control of motor speed is needed. Practical details such as component parameters are discussed to guide designers in identifying the link between critical performance requirements and component selection. The paper includes discussion of circuits which mitigate EMC issues inherent in switching supplies and power stages. Attention is also paid to ancillary design topics such as reverse battery protection, overvoltage due to load dump, thermal issues, and other fault-tolerant considerations. Compared to previous papers, the intent is to discuss the application with a holistic view, considering the practical interrelations between the various circuits and functions. The final design hardware is discussed, with test results showing comparison to expected performance. Lessons learned provide guidance for similar designs, with variations for increased power applications, or alternate loads, such as direct-drive or gear-driven positioning systems. Figure 1 Controller board and BLDC-driven pump
Kinnaird, Clark
A Hybrid Electric Vehicle Thermal Management System - Nonlinear Controller Design2015-01-17104/14/2015
The components in a hybrid electric vehicle (HEV) powertrain include the battery pack, an internal combustion engine, and the electric machines such as motors and possibly a generator. These components generate a considerable amount of heat during driving cycles. A robust thermal management system with advanced controller, designed for temperature tracking, is required for vehicle safety and energy efficiency. In this study, a hybridized mid-size truck for military application is investigated. The paper examines the integration of advanced control algorithms to the cooling system featuring an electric-mechanical compressor, coolant pump and radiator fans. Mathematical models are developed to numerically describe the thermal behavior of these powertrain elements. A series of controllers are designed to effectively manage the battery pack, electric motors, and the internal combustion engine temperatures. These controllers regulate the refrigerant compressor, coolant pump, and cooling fans to minimize the temperature fluctuations while reducing the overall cooling system power consumption. Simulation results for assault and convoy escort driving cycles are presented to show that the controllers meet the powertrain heat removal requirements. The battery core temperature can be tracked to within 0.8 °C of the target value, the internal (stator) temperature of electric motors can be maintained within 1.1 °C of the desired value. The coolant temperature at engine's outlet exhibited a 0.4 °C error range from the prescribed target value of 90 °C. The overall auxiliary power consumption of the cooling system is reduced by 45% when compared to a conventional cooling control method.
Tao, Xinran, Zhou, Kan, Ivanco, Andrej, Wagner, John R., Hofmann, Heath, Filipi, Zoran
Noise, Vibrations and Combustion Investigations of Preheated Jatropha Oil in a Single Cylinder Genset Engine2015-01-16684/14/2015
High viscosity of vegetable oil causes ignition problems when used in compression ignition engines. There is a need to reduce the viscosity before using it as engine fuel. Preheating and pre-treating of vegetable oils using waste heat of exhaust gases is one of the techniques, which reduces the viscosity and makes it possible to use it as alternate fuel for some niche applications, without requiring major modifications in the engine hardware. Several applications such as decentralized power generation, agricultural engines, and water pumping engines, can use vegetable oils as an alternative fuel. In present investigation, performance, combustion, and emission characteristics of an engine using preheated 20% blend of Jatropha oil with mineral diesel (J20) has been evaluated at a constant speed (1500 rpm) in a single cylinder four stroke direct injection diesel engine. Analysis of cylinder pressure, rate of pressure rise, heat release rate and cumulative heat release was done in addition to engine performance parameters such as brake thermal efficiency, brake specific fuel consumption and brake specific energy consumption. Regulated emissions such as CO, CO2, THC, NO and smoke were also measured in this comparative study. Since noise regulations are becoming stringent, therefore noise levels were measured (dBA) and combustion noise was calculated from cylinder pressure data from combustion analysis of the engine. Vibrations were measured using accelerometers at vertical, lateral and longitudinal directions. Noise and vibration analysis of the engine has also been carried out to assess vegetable oil's performance on these parameters vis-a-vis baseline mineral diesel.
Patel, Chetankumar, Tiwari, Nachiketa, Agarwal, Avinash Kumar
Testing and Development of an Enhanced and Cost Effective Engine Split Cooling Circuit2015-01-16504/14/2015
The drive to reduce CO2 and fuel consumption from passenger cars requires improvements from various subsystems. In particular, the ever growing importance of effective and efficient thermal management will no doubt benefit the quest for more efficient vehicle. While many established automakers have decided to increase the sophistications of the engine cooling circuits through electronics, the increase in complexity and costs are still not desirable especially for A and B passenger car segments. With this in mind, simple mechanical based cooling systems with enhanced functionalities are in high demand. To meet such demand, a simplified engine split cooling circuit previously proposed, simulated and reported seems to be promising. To further verify the indicated advantages, a prototype unit was built and physically tested using a dynamometer with motoring capability. The test results obtained are encouraging with several distinctive advantages over the conventional serial and parallel cooling circuits. With low circuit pressure losses, the cabin heater can be placed in between the engine and radiator thus eliminating the need for as much as 40 LPM of coolant to be returned to the water pump to avoid flow stagnation. With a lot more coolant flow going to the radiator, the standard water pump pulley was replaced with a bigger one to reduce the flow rate and the pump's power consumption. Engine FMEP measured using motoring dynamometer showed reduction in power consumption across the engine speed. With higher flow rate and flow velocities across the cylinder head combined with lower coolant temperature inside the cylinder head, the knock resistance of the engine is improved significantly. Spark ignition timing sweep using RON 95 fuel has also shown significant spark advance potentials across the engine speed. The positive test results obtained so far have proven that the proposed simplified engine split cooling has a big potential to meet the demands of future engines.
Osman, Azmi, Hussin, Mohd Asmu'i, Zainal Abidin, Shaiful Fadzil
A Smart Engine Cooling System - Experimental Study of Integrated Actuator Transient Behavior2015-01-16044/14/2015
Smart thermal management systems can positively impact the performance, fuel economy, and reliability of internal combustion engines. Advanced cooling systems typically feature multiple computer controlled actuators - a three way smart valve, a variable speed pump, and a variable speed electric radiator fan(s). To investigate the contributions of these electro-mechanical devices, a scale multifunction test bench was constructed which integrated these actuators, accompanying system sensors, and a controllable engine thermal load with real time data acquisition and control hardware/software. This paper presents a series of experimental studies that focus on the engine's thermal transient response to various actuators input control combinations. The test results established a basis for several key operating conclusions. First, the smart valve and variable speed pump impact the engine temperature by changing the heat transfer rate between the engine and the radiator through coolant redirection and/or coolant flow rate. On the other hand, the radiator fan(s) operation affects the engine's temperature by changing the heat rejection rate of the radiator which can influence the entire cooling system. Third, the smart valve's operation changes the engine's temperature magnitude the greatest amount (4.0%) followed by the radiator fan(s) (1.6%) and coolant the pump (0.5%). Finally, from a power consumption aspect, the radiator fan(s) consumes the most engine power in comparison to the two other actuators. Overall the experimental results offer insight to the control engineers for creating the frame work for advanced engine cooling system control algorithms.
Wang, Tianwei (Thomas), Wagner, John R.
Tailored Design and Layout for Loss Minimization or Cost-Effective Commonality of Parts - A Contradictory Conflict2015-26-00191/14/2015
In order to minimize the development and production costs in the automotive industry, despite steadily increasing variety of models and applications offered by the OEMs, the pressure on standardization of components and production processes is increasing continuously. As a direct consequence, modular engine families are already established with high degrees of common parts and kits as well as standardized interfaces for all vehicle platforms by most manufacturers these days. At the same time, the world adopted and announced massive legal demands concerning the reduction of CO2 emissions for the entire vehicle fleet. In addition to the optimization of the combustion process, the exhaust gas aftertreatment and thermal management, the use of improved and more resilient materials for higher reduction of mechanical friction leads to a significant amount of the realized lowering in fuel consumption respective CO2 emissions. Significant future potential for friction reduction and loss minimization is expected to result from, for example, one for the particular application optimized, on-demand component dimensioning and tailored calibrations. This dedicated fine-tuning approach is contrary to the widely spread application of a clear common part strategy. In the course of this paper the question will be discussed whether the additional cost of a component diversification can be justified within an engine family in contradiction to a best cost approach by using the scaling effects of parts communization.
Bick, Werner, Cevik, Cagri, Steffens, Christoph
A Secondary De-Aeration Circuit for an Engine Cooling System with Atmospheric Recovery Bottle to Improve De-Aeration2014-01-23429/30/2014
In any engine cooling system, de-aeration capability of the system plays a very critical role to avoid over heating of an engine. In general, with recovery bottle engine cooling system there is one vent hose from radiator pressure cap to the recovery bottle and coolant in the bottle is exposed to atmospheric pressure. From this vent hose air bubbles will move to recovery bottle from the engine and radiator when pressure in the system exceeds pressure cap setting. With this arrangement, de-aeration from the engine will happen when thermostat opens only and till that time air bubbles will be in the engine only and in this time there will be chance of overheating at some critical conditions because of air pockets in to the engine water jacket and the entrained air in the cooling circuit. Also, secondly 100 % initial filling cannot be achieved. Thus there is a need for continuous de-aeration irrespective of the thermostat opening/closing position and also to reduce number of filling intervals. This paper reports on improvement of de-aeration by adding a secondary de-aeration circuit for an engine cooling system with recovery bottle for a single cylinder light commercial vehicle. The secondary de-aeration circuit enabled continuous de-aeration for the cooling system with recovery bottle which performs with similar principle of cooling system with degas bottle and also reduced the number of filling intervals during the de-aeration test. This arrangement can be done to get weight and cost benefits over degassing tank, wherever it is technically possible (i.e. Radiator coolant inlet port should be higher than the engine coolant outlet port). The secondary vent added between top most point of the engine before thermostat valve to the radiator filler neck. A study was carried out on a vehicle with and without a secondary vent in the cooling system with respect to De-aeration, Initial filling capacity and Filling time. The test results confirmed significant improvement of de-aeration and initial filling capacity by adding secondary de-aeration circuit for an engine cooling system with recovery bottle.
Brahmasani, Lakshmaiah, Solomon, Samson, Khan, Parvej
Cooling System Optimization for a 3 Cylinder Naturally Aspirated Inline Diesel Engine2014-01-23389/30/2014
This paper involves increase in engine power by increasing bore size and stroke length along with other required engine level design modifications. Main focus is on addressing the cooling related issues by optimizing the cooling jacket design and water pump flow parameters. Engine cooling requirements need to be upgraded to address increase in thermal loads because of reduction in cooling area between cylinder block and cylinder liner due to increase in bore size keeping engine block size fixed. Methodology used is cooling jacket optimization and water pump design modifications. In internal combustion engines, cooling system involves a complex geometry of water jackets. For such complex systems, CFD simulations can be executed in a short period of time and are relatively inexpensive. CFD provides the ability to theoretically simulate any physical condition. Effective utilization of STAR CCM+ V8.04 is done for water jacket design of a 3 cylinder water cooled inline diesel engine. k-ε turbulence model was used for the present study. Coolant flow velocity and temperature distribution was used for study. Cylinder block and cylinder head were modeled in UG NX 7.5.
Kale, Vishal, Dharan Raju, Bharani, Dhiman, Vikas
Heavy Duty Vehicle Cooling System Auxiliary Load Management Control: Evaluating the Maximum Gain of Implementing an Advanced Control Strategy2014-01-23419/30/2014
Vehicle thermal management covers the engineering field of solutions that maintain the complete vehicle in acceptable operating conditions regarding component and fluid temperatures in an engine. The maximum efficiency rating of a Diesel engine reaches up to 45%. In order to improve the fuel efficiency of the vehicle one can reduce the losses generated by the cooling system. Ideally, the full motive force of the engine should be used for propulsion and new and more efficient energy sources have to be explored to power the secondary systems (cooling, compressed air…). This paper introduces a dynamic programming algorithm which is used to determine the maximum gains during operation for a given architecture of the cooling system of a Heavy Duty Truck. The algorithm, based in Bellman principle, will determine the best control trajectory for the pump and the fan according to energetic and control goals (fuel economy, regulation of temperature…). For this purpose, a reduced model of the cooling system based on energy balance equations has been determined and validated through simulations. An optimal control path is determined by the algorithm for a given cycle, which is then used as an input to the controllers in a simulation platform for the same reference driving cycle in order to calculate more accurately the energy consumption. The simulation platform is built in GT-Suite (system model) and Matlab/Simulink (inputs). The result show how it is possible to reduce the energy consumption by optimizing the control strategy of the cooling system, in particular hints are given in terms of thermostatic valve threshold tuning.
Sermeno, Salvador, Bideaux, Eric, Morgan, Tessa, Nguyen, Duc
Design Optimization of FEAD System to Meet Durability Target in a New Vehicle Development Program2014-01-16364/1/2014
Front end accessory drive (FEAD) system explained in this paper is a sub-system of an engine. In FEAD system, a poly-v belt is used to drive the alternator and water pump by transmitting power from crankshaft pulley. In a new vehicle development program, durability targets of FEAD system are based on required life of poly-v belt, its static tension readjustment interval and replacement frequency. To meet these durability targets following methodology is applied in design stage:- 1 Simulation of FEAD system to calculate the theoretical life of belt 2 Part level testing of belt as per SAE J2432 These methods give sufficient information on belt durability. However in actual usage, certain failures are prone to happen and enormous difference is always observed between theoretical and actual life of belt. This paper describes the traditional stair-case approach followed to optimize the FEAD system based on the outcome of durability tests. Component level test results of poly-v belt, like belt elongation and belt wear verified in actual engine level testing for improving the belt durability. General test duration for durability is approximately 40 working days depending upon test hours. This paper describes the check points and criteria to predict the performance of 40 days of durability test on the basis of initial 10 days (which is very practical) for evaluation of design changes thereby saving significant amount of development time.
Kumar, Narinder, Gautam, Amit, Gupta, Vineet
Drive Cycle Simulation of A Tiered Cooling Pack Using Non-Uniform Boundary Conditions2014-01-06544/1/2014
In a tiered cooling pack, the airflow through the individual heat exchangers is determined by the package and aperture lay out. Each heat exchanger rejects heat as a function of the internal coolant flows, the cooling airflow and the air temperature. In a typical automotive cooling pack, the cooling airflow will be non-uniform in velocity and temperature due to fans, aperture geometry, exterior flows, heat exchangers and recirculation. In a drive cycle, these boundary conditions will change with vehicle operating conditions like vehicle speed, engine speed, ambient temperature, and altitude. These non-uniform conditions on the cooling pack can lead to significant errors when uniform boundary conditions are assumed in a transient simulation. This error is commonly corrected using vehicle test data. A predictive approach, which eliminates the need for correlation vehicle testing, is presented. This methodology uses a full vehicle airflow simulation in PowerFLOW to determine boundary conditions at the entrance and exit of the cooling package at stabilized operating conditions. GT Suite is used to model the heat exchange and fluid flow within the cooling package. The radiator heat rejection is modeled solely from component characterization. The boundary conditions over the drive cycle are determined by interpolation of the PowerFLOW results and adjustment for ambient conditions. This methodology was applied to the Jaguar XJ, with a two-tier cooling pack, executing a high speed transient drive cycle at the Nurburgring circuit. This methodology predicted transient coolant temperatures to a high level of accuracy from component data and vehicle geometry.
Jansen, Wilko, Amodeo, Joe, Tate, Edward, Yang, Zhongzhou
Efficient Thermal Modeling and Integrated Control Strategy of Powertrain for a Parallel Hybrid EcoCAR2 Competition Vehicle2014-01-19274/1/2014
Hybrid electric vehicle (HEV) is one of the most highly pursued technologies for improving energy efficiency while reducing harmful emissions. Thermal modeling and control play an ever increasing role with HEV design and development for achieving the objective of improving efficiency, and as a result of additional thermal loading from electric powertrain components such as electric motor, motor controller and battery pack. Furthermore, the inherent dual powertrains require the design and analysis of not only the optimal operating temperatures but also control and energy management strategies to optimize the dynamic interactions among various components. This paper presents a complete development process and simulation results for an efficient modeling approach with integrated control strategy for the thermal management of plug-in HEV in parallel-through-the road (PTTR) architecture using a flexible-fuel engine running E85 and a battery pack as the energy storage system (ESS). While the main motivation for the work is to deliver a design for the Department of Energy's EcoCAR2 Plugging in to the Future Competition, yet the framework and methodologies should be useful for any typical hybrid powertrain thermal and control development. The frameworks of this project include simulating the thermal behavior of major HEV powertrain components using system oriented models more suitable for real-time vehicle operations. A comprehensive control algorithm is established in a Thermal Manager, as part of vehicle supervisory controller. Finally, the proposed model is tested through realistic driving conditions to demonstrate reliability.
Cao, Mengjia, Kovent, Idan, Ku, Jerry
Modeling of a Thermal Management Platform of an Automotive D.I Diesel Engine to Predict the Impact of Downsizing and Hybridization during a Cold Start2014-01-06574/1/2014
Thermal management is a key issue to minimize fuel consumption while dealing with pollutant emissions. It paves the way for developing new methods and tools in order to assess the effects of warm up phase with different drivetrains architectures and to define the most suitable solution to manage oil and coolant temperatures. DEVICE (Downsized hybrid Diesel Engine for Very low fuel ConsumptIon and CO2 Emissions) project consists in designing hybrid powertrain to cut off significantly CO2 emissions. It combines a 2-cylinder engine with an electric motor and a 7-gear dual clutch transmission. Hybridization and downsizing offer a great improvement of fuel economy and it is valuable to study their effects on thermal management. Hence, a dedicated AMESim platform is developed to model the fluids temperatures as well as the energy balance changes due to the powertrain architecture. After using a 4-cylinder reference engine to validate the model, the warm up phase (comparing hot and cold start NEDC) leads to a 12% fuel consumption penalty with DEVICE powertrain. Hybridization and downsizing save up respectively 7% and 11% on cold start (20°C) NEDC. Since energy balance is changed compared to reference engine, new technologies, such as electric water pump, resizing oil/water exchanger and so on, should be used to enhance fuel economy and the modelling platform enables to study their effects.
Rabeau, Fabien, Magand, Sebastien
Glossary of Engine Cooling System TermsJ1004_201402 (Historical)2/7/2014
The objective of this glossary is to establish uniform definitions of parts and terminology for engine cooling systems. Components included are all those through which engine coolant is circulated: water pump, engine oil cooler, transmission and other coolant-oil coolers, charge air coolers, core engine, thermostat, radiator, external coolant tanks, and lines connecting them.
Cooling Systems Standards Committee
Drivetrain Energy Distribution and Losses from Fuel to Wheel2013-01-911811/20/2013
Depending on a vehicles drive cycle, an improvement of the overall drivetrain efficiency does not necessarily have to go along with an improvement of its mileage. In here the ratio of energy to overcome rolling resistance, aerodynamic drag, acceleration and energy wasted directly in wheel brakes is responsible for potentially differing trends. A detailed knowledge of energy flows, sources and sinks makes up a substantial step into optimizing any drive train. Most fuel energy leaves the drivetrain via exhaust pipes. Next to usable mechanical energy, a big amount is spent to heat up the system directly or to overcome drive train friction, which is converted into heat to warm up the system additionally. An in depth quantification of the most important energy flows for an upper middle-sized class gasoline powered drive train is given as results of warm-up cycle simulations. Combustion engine heat losses are split into four paths to be compared with the heat of ten engine friction components. Total engine friction of engines, started at room temperature in low load cycles used for emission legislation, makes up about one third of the heat input of the thermal system. Energy flow manipulation in terms of thermal management measures are quantified as well as secondary effects and benefits seen in a holistic approach covering all relevant paths from fuel to wheel. Investigated is the effect of a split cooling system, a map controlled thermostat, the use of an electric water pump and combinations of those for a cold started FTP75 test cycle. Split cooling yields a benefit of ∼ 2.2 - 2.4 % fuel reduction potential; the use of an electrical water pump shows ∼ 0.3 - 1.2 %. The benefit of a combination of both measures is simulated to∼ 2.3 - 2.5 %.
Beulshausen, Johannes, Pischinger, Stefan, Nijs, Martin
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