Browse Topic: Throttles

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Control and Validation of an Autonomous Drag Racing Vehicle2021-01-01014/6/2021
This paper studies the implementation and validation of control algorithms for an autonomous drag racing vehicle. The previously developed modeling equations are first implemented with control in a realistic simulation environment complete with synthetic sensor data and decision-making algorithms. The controller is then transformed into an embedded on-board processing unit for on-vehicle testing. Camera, lidar, and radar sensor data are investigated and algorithms are created to provide information from physical sensors rather than synthetic data. The control related to actuation of the steering, brake, throttle, and shifting systems are further discussed, along with human-vehicle interaction in terms of handoff and emergency takeovers. The control algorithms are then validated on the research vehicle. This is demonstrated by completing a fully autonomous quarter-mile drag race, complete with camera detection for the staging sequence and MPC trajectory following. Two additional safety scenarios are presented and controlled: starting the race off center and fishtailing.
Donikian, Vatche, Bell, Joseph, Khairallah, Nadim, Washington, Gregory
Maximum Exterior Sound Level for SnowmobilesJ192_202103 (Current)3/1/2021
This SAE Standard establishes the instrumentation, test site, and test procedure for determining the maximum exterior sound level for snowmobiles.
Snowmobile Technical Committee
Transformational Technologies Reshaping Transportation - An Industry PerspectiveSAE-PP-003372/26/2021
Freight trucking has always embraced continuous improvement although the general public may be largely unaware of the tremendous changes that have occurred to date in vehicle safety, efficiencies, emissions mitigation and asset utilization. Today’s freight industry is in the early stages of dramatic technological advances in areas such as connectivity, automation and electrification. Fleet and manufacturer perspective on these transformational technologies are universally supportive, driven both by economic and regulatory factors. The early stages of these technological revolutions are characterized by a multitude of competing concepts confusing choices, complicated by a significant number of competing vested interests obscuring objectivity, and clouded by billions of dollars of venture capital. The objective of this report is to provide unbiased insight into the freight industry’s thoughts on these transformational technologies.
Mutagaana, Festo, SintzUSER, Jeneane
A New Image De-hazing Method for Safety Critical ADAS ApplicationsSAE-PP-003122/19/2021
Driver safety and Advanced Driver Assistance Systems (ADAS) is gaining lot of importance these days. In some countries, there are strict regulations in place which mandate the use of certain ADAS features in automobiles. However, as the need for these safety critical systems increases, the challenges associated also increase. These challenges can arise due to technology, human factors or due to nature. In countries like India, where one can expect different weather conditions with changing geography, the associated challenges are mainly due to the natural factors like haze, fog, rain and smoke. This poses a challenging problem in terms of visibility for the drivers as well as in vision based ADAS; thereby, leading to many fatal road accidents. In this paper, a novel pre-processing technique, which addresses the interesting problem of enhancing the perceptual visibility of an image that is degraded by atmospheric haze, is proposed. The solution to this problem is presented by combining model (Beer Lambert model) based and non-model based technique of haze removal. The combined hybrid model picks the best haze free image from the series of non-hazy outputs, that are derived based on multiple scattering coefficients of the input hazy image. The idea here is to restore the true color of an image that is affected by the atmospheric haze. In comparison with the state of the art methods that are available in literature, the proposed method is shown to be capable of recovering better haze-free images both in terms of visual perception and quantitative evaluation. The proposed method promises better perceptual understandings and visibility restoration for vision based ADAS under hazy driving conditions.
Mutagaana, Festo, SintzUSER, Jeneane
7.0.102 - Prescriptive Modeling, Simulation and Performance Analysis of Mild Hybrid Vehicle and Component OptimizationSAE-PP-002782/4/2021
Reckoning today's environmental rules, legislative regulation and market requirements- the automotive industry of late has witnessed an increased vigor and enthusiasm by auto makers towards electrification of vehicles across all platforms in a bid to improve fuel economy and performance. Hybridization of a vehicle often involves the use of expensive high performance motors and large battery packs. However due to the challenges associated with the packaging of bulky battery and motor systems in existing drive train, mild hybrid systems have been preferred over strong or full hybrids especially in current production models as they don't entail any major change in architecture and the reduced battery size, both of which provide for easier packaging of components. In this paper the authors present a generic model of a mild hybrid vehicle that can be effectively used to simulate any vehicle, enabled with a mild hybrid system to predict with approximate certainty the improvement in performance parameters and optimize component size. Thus, assist in selection and sizing of motor, battery and the associated operation voltage, with minimal monetary expense and time consumption. Consequently, an optimal system configuration for the prototype build is arrived while resulting in significant cost and time savings.
Lname, Fname
6.0.117 - Definition of a Protocol of Automatic Identification and Notification of Road Accidents and Development of an Advanced eCall SystemSAE-PP-002722/4/2021
The eNOTIFY project defined an algorithm which allows the vehicle to recognize when an accident has occurred and what kind of accident has taken place (frontal, side, roll-over or rear-end collision). The innovative aspects of this methodology are basically that, for each type of accident and for each class of vehicle, a maximum and minimum level of vehicle accelerations (linear or angular) are defined for the severe accident, slight accident and no accident scenarios. A direct application of this algorithm could be to include it in an on-board unit on vehicles, and use it in emergency call applications. eCall devices have been developed to automatically notify emergency services in the event of an accident, in which a fast and efficient rescue operation can significantly increase the chances of survival of the severely injured. In order to reduce response time and improve the efficiency of the medical and technical services, fast and accurate accident identification is required. This on-board algorithm makes it possible to identify the type and severity of the accident allowing emergency services to respond accordingly; and as such could contribute to saving lives.
Mutagaana, Festo
6.0.102 - FeSnSAE-PP-002582/4/2021
The aim of this study is to develop the simple approach to produce iron-tin (Fe-Sn) intermetallic compound for EV battery anode materials. Intermetallic FeSn2 compound was synthesized by two step method. Mechanical alloying of Fe and Sn element powders with equal atomic ratio was performed for 25 h. The mechanically alloyed powders compacts were processed via liquid phase sintering, in which the powders compacts were heated at different temperatures and for 10 min. The experimental materials were characterized by X-ray diffraction, scanning electron microscopy and thermal analysis techniques. The FeSn2 compound was formed during liquid phase sintering. However, the reaction between Fe and Sn was incomplete under the investigated sintering time of 10 min.
Mutagaana, Festo
6.0.113 - Measuring Smoke Emissions from Different Generations Diesel Passenger Cars in Antwerp-Belgium During Winter and SpringSAE-PP-002442/3/2021
More than 600 passenger cars were measured during winter and spring at the end of 2012 beginning 2013 in Antwerp Belgium in order to determine the effect of mileage and year of first registration on smoke emissions or smoke opacity from diesel light duty vehicles. All measurements were contacted in two different campuses of the University of Antwerp and under different ambient conditions. Various parameters such as ambient temperature, ambient humidity, car age, number of passengers in each cars, time of measurement etc. were taken into account and presented in this paper. All findings from these set of measurements were split into two big categories, those cars with less than 150,000km on the clock and the second one with those cars with higher number of mileage. The effect of ambient temperature but also the mileage on smoke opacity will be presented and discussed in more details. Smoke emissions are dependent also on ambient humidity and in this study will be considered the important role that humidity plays in total smoke opacity from various diesel engines. Finally the effect of mileage on smoke opacity is something that will be also examined and discussed intensively. Last but not least, a comparison between two similar cars equipped with the same engine in terms of capacity but fitted with standard and tuned electronic control unit (ECU) respectively was done and interesting findings will be shown in this work.
Mutagaana, Festo
Spark Arrester Test Procedure for Large Size EnginesJ342_202010 (Current)10/6/2020
This SAE Recommended Practice establishes equipment and procedures for the evaluation of the effectiveness and other performance characteristics of spark arresters or turbochargers used on the exhaust system of large engines normally used in a railroad locomotive, stationary power plant, and other similar applications. This document does not cover applications requiring flame arresting, exhaust gas cooling, or isolation from explosive gases. Two test methods are presented: a laboratory test using ambient air (cold test) and an engine test using exhaust gases (hot test). The hot test is preferred. Arresters tested by the provisions of this document can be expected to perform as tested when tilted no more than 45 degrees from their normal position. Test results from a spark arrester or turbocharger evaluated by the hot test can be applied to different engines of similar design, provided the data shows it to be effective in the applicable flow ranges. Certain design and performance characteristics, which represent current requirements by regulatory agencies for qualification and approval under this document, are listed in Appendix A.
SAE IC Powertrain Steering Committee
Coupled Pitch-Lag Hinge for High Inertia Electric RotorsF-0076-2020-1632710/5/2020
As rotor diameter and inertia increases, the quickness of the thrust response to pilot inputs slows, yielding negative implications to handling qualities and limitations on scaling electric propulsion. This study presents a novel approach to alleviating these scaling effects by introducing a pitch-lag coupled hinge to the root of 40" and 50" diameter props. The impacts of chordwise hinge placement and hinge angle are examined and compared to a baseline rigid rotor to provide physical understanding of the rotor dynamics. It is shown that a coupled hinge can be designed to maintain propeller efficiency for a design thrust, while increasing the sensitivity of thrust to rotor speed and the maximum thrust of an RPM-limited rotor. Finally, the dynamic implications of this are tested using a first-order motor model. When a 40" diameter trimmed rotor is set to max throttle, rotors with a coupled hinge angle achieve a 6% higher thrust in 9% less time. The dynamic response improvement scales favorably when the rotor diameter is increased. For the 50" diameter rotor, the introduction of pitch-lag coupling reduces the time constant of the rotor’s thrust response by 32%.
Reddinger, Jean-Paul
Maximum Sound Level Potential for MotorcyclesJ47_202006 (Current)6/5/2020
This SAE Recommended Practice establishes the test procedure, environment, and instrumentation for determining the maximum sound level potential for motorcycles under wide open throttle acceleration and closed throttle deceleration.
Motorcycle Technical Steering Committee
Development of GM Allison 10-Speed Heavy Duty Transmission2020-01-04384/14/2020
This paper describes the development of the GM Allison 10-Speed Heavy Duty (HD) Transmission. The trend of increased towing capacity and engine horsepower in the automotive heavy-duty truck segment has been steadily climbing for the past 10 years. The development of 10-Speed HD Transmission is designed to be best in class in for towing performance in the 2500/3500 series segment while optimizing fuel economy. The 10-Speed HD Transmission also gives the customers the option to order an integrated power take-off (PTO) unit that benefits downstream installation of utility accessories such as hydraulic pumps, generators, etc.
Lee, Chi Teck, Ames, David, Caldwell, Brett, Knoth, Matthew, Reinhart, Timothy, Kelly, Jeffrey, Kannan, Rajesh, Tanasi, German
Fatigue Life Prediction of HVAC Pipe Assembly for Measured Powertrain Load by Virtual Simulation2020-01-01884/14/2020
Structural durability of automotive components is one of the key requirements in design and development of today’s automobiles. Virtual simulations are used to estimate component durability to save the cost and time required to build the components and testing. The objective of this work is to find the service life of automotive HVAC pipe assembly by calculating cumulative fatigue life for operation under actual powertrain load conditions. Modal transient response analysis is performed with the measured powertrain load time history. Strain based fatigue life analysis is carried out using modal superposition method (MSM). The estimated fatigue life was compared with the physical test results. This paper also explains the root cause of low fatigue life on pipe assembly and provide the solution.
Pandi, Sathish Kumar, Elango, C, Appana, Kameswara Rao, Mahadule, Roshan N., Krishna, DivaKaruni Murali
Integrated Exhaust Manifold Cylinder Head Design Methodology for RDE in Gasoline Engine Application2020-01-01694/14/2020
In recent years, worldwide automotive manufacturers have been continuously working in the research of suitable technical solutions to meet upcoming stringent Real Driving Emission (RDE) and Corporate Average Fuel Economy (CAFÉ) targets, as set by international regulatory authorities. Many technologies have been already developed, or are currently under study by automotive manufacturer for gasoline engines, to meet legislated targets. In-line with the above objective, there are many technologies available in the market to expand lambda 1 (λ=1) region by reducing fuel enrichment at high load-high revolutions per minute (RPM) by reducing exhaust gas temperature (for catalyst protection) for RDE regulation [1]. Integrated Exhaust Manifold (IEM) is the key technology for the Internal Combustion (IC) for the subjected matter as catalyst durability protection is done by reducing exhaust gas temperatures instead of injecting excess fuel for cooling catalyst. Additionally, this technology also helps in cost saving due to reduced parts count, in engine weight reduction, improve the response and increase fuel economy during the cold start stage of Modified Indian Driving Cycle (MIDC) and Worldwide harmonized Light vehicles Test Cycles (WLTC) by faster warm-up of coolant in cold stage and also fuel enrichment reduction (reduced fueling requirement) in high-speed regions of these cycles as shown in Figure 1.
Singh, Amandeep, Singh, Jaspreet, Poonia, Sanjay, Jalan, Ankit, Kumar, Narinder, Sharma, Shailender, Agarwal, Deepali, Puri, Kushal
Spectroscopy Based Tool for Temperature Evaluation during the Spark Discharge2019-32-05021/24/2020
In this work, a new tool is proposed and tested to investigate the early phase of spark ignition (SI) processes. The diagnostic tool is based on Spark-Induced Breakdown Spectroscopy (SIBS), a consolidated technique in which the plasma formed by spark generation between two electrodes is used as the excitation source for optical emission spectroscopy (OES). The spark discharge of a commercial ignition system was analyzed through OES to correlate the characteristic evolution of the discharge with the formation of reactive species inside the activated volume. Specifically, an open-source spectrum simulation program (Lifbase) together with the NIST database was used for defining relations between the ultraviolet emission bands of nitrogen first negative system (FNS_N2) in the glow phase for different plasma temperature and pressure values. Besides plasma density and ion energy, electron and gas temperatures are important parameters that govern the reaction rate of active species generation through dissociation, excitation, and ionization processes and thus influence the chemistry of the spark discharge. It is well known that the electrical discharge occurring between the spark plug electrodes can be divided into three phases (breakdown, arc and glow discharge), characterized by different time scales. The breakdown occurrence causes the gas molecules in the ignition area to break into atoms and ions. Molecular recombination starts after some hundreds nanoseconds from breakdown, thus leading to significantly different spectral emissions. Consequently, if measurements are triggered after the time at which breakdown occurs, molecule and molecular radical bands will be dominating in the spectral emission instead of the atomic lines. The proposed methodology takes advantage of the peculiarity of N2 molecules to exchange rotational and translational energy with heavy particles faster than with electrons. For this reason it is possible that rotational distributions quickly achieve thermodynamic equilibrium with the bulk gas. Therefore, a convenient way to determine the gas temperature is through the measurement of the roto-vibrational band spectrum of nitrogen. The validation of the developed tool was performed by considering the emission of excited species detected in ambient conditions. Successively, the methodology was applied in an optically accessible combustion chamber of a spark ignition research engine under motored and fired conditions, and further validated by temperature evaluations based on CN and OH emission bands ratio. The proposed tool allowed obtaining deeper insight into the complex physical and chemical phenomena underlying the ignition event.
Merola, S., Irimescu, A., Vaglieco, B.M., Di Iorio, S., Sementa, P.
Tumble Flow Enhancement Applied for Low-Load Condition of Engines by Utilizing Reverse Flow Phenomenon in Intake Port2019-32-05091/24/2020
We established a technology that can enhance the tumble flow in the cylinder only in a partial load range of the engine without the need to use any intake path switching mechanisms. Firstly, we attempted to understand the basic phenomena of intake flow by using a CFD model, while using a butterfly throttle valve in a straight pipe. By doing this, we were able to observe the reverse flow of intake air that appears after the intake air has passed the throttle valve when the throttle valve opening is 30% or less. This reverse flow is generated mainly in the flow that has passed the trailing edge of the throttle valve. At both sides of the trailing edge opening, the flow is slowed down by diffusing. The flow is then pulled into the low-pressure zone created behind the throttle valve. In addition, a part of the reverse flow merges with the air flowing on the leading-edge side. Next, we confirmed that installing a flow separator behind the throttle valve that vertically divides the flow can successfully capture the reverse flow into one of the two flow paths. Furthermore, we confirmed that optimizing the separator position can capture most of the flow into one path, thereby gaining the required amount of flow that can generate tumble in the combustion chamber. By applying the above results to an actual engine, we validated the effect through a CFD flow analysis and also steady flow tests. As a result, we confirmed that this system can enhance tumble within a partial load range of the engine to a level that is equivalent to that obtained by a tumble port that has a flow path switching mechanism.
Nakamura, Yohei, Inoue, Yosuke, Fujikubo, Makoto
Simulation Analysis of the Scavenging Process of a Uniflow and Loop Scavenging Concept2019-32-05491/24/2020
The two-stroke engine, as a today unconventional concept in automotive applications, has a great potential for a relaunch in the fast-growing market of Plugin Hybrid Electric Vehicle (PHEV) or Range Extender Electric Vehicle (REX) [2, 3, 4, 8, 9]. An efficient scavenging to remove the in-cylinder burnt gases and to fill the cylinder with fresh charge, performed at the same time is one of the major challenges, as losses of fresh air and fuel towards the exhaust line should be avoided when operating a lambda = 1 concept necessary for a 3-way catalyst aftertreatment system. A prior study [1] of different gas exchange designs for two-stroke engines concludes that two possible concepts cover this purpose. In this paper, 3D-CFD simulation is used to compare these two different scavenging concepts, a uniflow and a loop scavenging type with control elements for the gas exchange process. As boundary conditions, it is assumed that both concept types have nearly the same displacement, are used with an external scavenging blower and have a lubrication system like a conventional oil sump similar to a four-stroke engine. Additionally, a high-pressure direct injection fuel system is applied to guarantee oil- and fuel-free air for the scavenging process. To compare these different two-stroke scavenging concepts, this study focuses on the scavenging and compression phase using 3D-CFD simulation in order to evaluate the scavenging characteristics and the in-cylinder charge motion. The goal of this study is to prepare a basis for discussion of the best configuration, which will be designed, built and tested on the engine test-bench.
Sturm, Stefan, Lang, Michael, Schmidt, Stephan
Maximum Exterior Sound Level for SnowmobilesJ192_202001 (Historical)1/15/2020
This SAE standard establishes the instrumentation, test site, and test procedure for determining the maximum exterior sound level for snowmobiles. Sound propagation is directly related to the ground cover and provides the largest variation to the measured result. A correction factor is introduced to improve year-round test repeatability of the results on grass surfaces by correcting their spectrum to be similar to snow-covered spectra. Measured sound pressure levels are also highly dependent on the degree of track slip present when performing the vehicle acceleration. Operators should attempt to limit track slip as much as possible while maintaining the requirements described in 5.1.1.
Snowmobile Technical Committee
An Effect of Utilization B30 from Various Blends of B0:FAME and HVO on Emissions, Fuel Consumption and Power of Euro4 Vehicle Technology2019-01-218912/19/2019
Indonesia has implemented mandatory for utilization of high ratio biodiesel starting from B10 (10% of biodiesel and 90% of diesel fuel by volume) in 2013 then it gradually increased to B20 in 2016 and B30 in 2020. On the other hand, Indonesian Government will also strengthen vehicle emission regulation from Euro 2 to Euro4 in 2021. Therefore, B0 (low sulfur diesel fuel) and B100 (biodiesel) fuel properties as blended fuel for B30 must be improved to comply with Euro4 vehicle emission regulation. In this study various formulation of B30 were investigated, in which the B100 was varied from FAME (fatty Acid Methyl Ester), HVO (Hydrotreated Vegetable oil), and blend of FAME and HVO. The test was conducted under Euro4 vehicle technology to investigate their effect on emissions, fuel consumption and power. In this experiment, emission, fuel consumption and power were tested using UN-ECE R83-05 regulation, UN-ECE R101 and acceleration method respectively. The results showed that B30 has lower CO, HC and particulate emission compared with B0. However, NOx emission for some formulation slightly increased. Moreover, B30 could comply with emission limit, as stated under Euro4 regulation. Fuel consumption for B30 with some formulation was 2-3% higher than that of B0, but it was about the same between B0 and B30 with optimization ratio of FAME and HVO.
Setiapraja, Hari, Yubaidah, Siti, Ekasari, Mutia, Haspriyanti, Nita, Rustyawan, Wawan, Rochim, Abdul
Disc Thickness Variation (DTV) Operational Measurement and Influence on the Overall Vehicle Roughness2019-01-21109/15/2019
The brake disc or rotor design is one of the main concerns in the development of the vehicle brake system. One of the key factors of its drawing and manufacture is related with the thermo-mechanical deformation that can transmit further vibrations to the complete vehicle. This phenomenon, called brake judder or roughness, can appear in both cold and hot brake conditions, the latter being especially affected by the thermal factor. The evolution of the disc shape fluctuation and Disc Thickness Variation (DTV) is usually illustrated before and after a test, reflecting typically the same output. However, the real transient disc behavior during these phases is rarely measured and is difficult to determine. The reality is that most of the time, some unexpected deformations may appear, these being the final root cause of the excitation of judder vibration. During the cold judder, the disc starts at a low temperature and controlled DTV, which corresponds to the disc’s natural shape and is only affected by the wear conditions. On the other hand, hot judder is performed by repeating consecutive snubs, heating up the rotors to a high temperature and assessing the roughness in those ranges. In this case, not only the DTV evolution during the stop is important, but also the change between each snub, according to the temperature increase. All in all, the methods presented in this study become a strong tool for understanding how real and operational measurements are done, and how they can be effective for problem solving activities and useful for validating component design developments.
Ferrer, Bernat
Potential to Reduce Nano-Particle Emission in SG-DISI Engine with Normal Butane2019-24-00229/9/2019
Lean stratified combustion is a mean to dilute the fuel-air mixture leaner than stoichiometric ratio, by using stratification of fuel gradient in a spark ignition engine. Under the lean stratified combustion, differed from the stoichiometric homogeneous charge combustion, flame could propagate through extremely rich air-fuel mixture, while the global air-fuel mixture is under lean condition. The rich mixture causes considerable amount of particulate matter, but, due to large effect of efficiency improvement, the attractive point is on fuel economy compare to homogeneous charge SI combustion. The easiest way to reduce particulate matter is changing fuel to gaseous hydrocarbon, to minimize evaporating and mixing period. In this study, to reduce the particulate emission and to develop the way to mitigation of emission, the emission data of particulate under low and medium-low load conditions from normal butane fueled research engine are dealt to optimize combustion strategies, with respect to injection and ignition. Especially, particulate number density were collected in the research engine, and the causes of particulate formation were studied with visualized combustion data. Through visualization data, the sources of particulate emission were collected through sooting flame position, and the characteristics. In the results of analysis, large amount of small particle source in combustion could be caused even in longer mixture formation time, which the more homogeneous mixture could constructed. These results were caused by multi-point diffusion burn phenomena in burned gas area, which was not observed in shorter timing gap from injection to ignition. The number emission were enhanced in appropriate time gap with higher work conversion efficiency, additionally with higher in-cylinder temperature circumstance. Faster combustion in the case caused more wetting and sooting flame on components such as injector and spark plug, in addition to sooting flame before the flame let. In addition, the particle size distribution were shift toward larger size with the sooting flame, and the numbers also were increased. To improve these emission, effort to accomplish with more momentum exchange in addition to evaporation. Nevertheless, the overly leaned mixture would deteriorate efficiency of the combustion and flame propagation, accompanying hydrocarbon and carbon-monoxide increase. With sweeping the spark and injection timing, the optimum for efficient and clean combustion could be found with retarded injection timings.
Park, Sangjae, Lee, Sanguk, Na, Yonghyun, Bae, Choongsik
Modeling of a Spark Ignition Engine with Turbo-Generator for Energy Recovery2019-24-00849/9/2019
Increasingly stringent regulations in the field of pollutant are forcing engine manufacturers to adopt new solutions to contain exhaust emissions, such as Hybrid Electric Vehicles (HEV) or Full Electric Vehicles (FEV). Still far from the wide diffusion of FEV limited from electrochemical storage systems together with the difficulty of creating adequate infrastructure distributed throughout the territory to recharging batteries, the HEV seems to be actually a better solution. The hybrid vehicle is already able to guarantee satisfactory autonomy and low pollution levels by combining the advantages offered by the two technologies of thermal and electric propulsion. Currently on the market there are several types of hybrid vehicles, with different degree of hybridization (electric motor power versus propulsion total power), capacity to store electricity and type of scheme constructive adopted for the integration between the thermal engine and the electric machine. A particular interest is getting the mild-hybrid (or light hybridization) and the micro-hybrid (or minimum hybridization) with 48V electrical system added to the classic 12V one. A possible solution could be the electric turbo-compounding system where a turbine coupled to a generator (turbo-generator) uses the exhaust gas flow of a reciprocating engine to harvest waste heat energy and convert it into electrical power. In this way, the power generated from the system can be used to feed local electrical loads such as engine auxiliaries, increasing the whole system efficiency. The present study deals with the simulation of a spark ignition engine, present in a test room of Istituto Motori (CNR), including a turbo-generator at the exhaust to evaluate the advantages in terms of overall efficiency. The internal combustion engine model was developed by using a 1D code (GT-Power software), while the turbo-generator and the electric system are described in the Matlab/Simulink environment. The results obtained showed an appreciable increase in the overall efficiency.
Arminio, Fabio, Cameretti, Maria Cristina, De Simio, Luigi, Iannaccone, Sabato, Terzo, Teodoro
Knock Mitigation by Means of Coolant Control2019-24-01839/9/2019
The possibility to mitigate the knock onset by means of a controlled coolant flow rate is investigated. The study is carried out on a small displacement, N.A. 4-valve per cylinder SI engine. The substitution of the standard belt-driven pump with an electrically driven one allows the variation of the coolant flow rate regardless of engine speed and permits, therefore, the adoption of a controlled coolant flow rate. The first set of experimental tests aims at evaluating the engine operating condition and the coolant flow rate, which are more favorable to the knock onset. Starting from this condition, subsequent experimental tests are carried out for transient engine operating conditions, by varying the coolant flow rates and evaluating, therefore, its effects on cylinder pressure fluctuations. In all the experiments, the spark advance and the equivalence ratio are controlled by the ECU according to the production engine map. The results show that the effects of coolant flow rate on in-cylinder pressure fluctuations are not negligible and the implementation of a predictive controller for the management of the coolant flow rate can be adopted for mitigating knock by limiting, therefore, the use of more fuel consuming strategies.
Perrone, Diego, Falbo, Luigi, Castiglione, Teresa, Bova, Sergio
In-Cylinder Flow Measurements in a Transparent Spark Ignition Engine2019-24-00999/9/2019
Flame development, combustion efficiency and emissions of a gasoline direct injection engine are strongly related with mixture preparation. Consequently, it is important to investigate the flow field and turbulence quantities at the parts of the thermodynamic cycle in which mixture preparation occurs. Flow field measurements were obtained by using 2D digital Particle Image Velocimetry technique in a 475cc optical single - cylinder Gasoline Direct Injection (GDI) spark ignition engine. The results include phase averaged velocity fields at 1000 and 1500 RPM with 100% and 25% throttle position. These sets of measurements were conducted for cold flow (motoring) conditions at three different planes including the tumble plane and the swirl plane. The flow was recorded at various crank angles between 340° and 20° before the combustion top dead center (BTDC) with an increment of 40°. The spatial averaged TKE (Turbulent Kinetic Energy) was calculated along with the TR (Tumble Ratio). It was observed that a tumble like motion with Counter Clock Wise rotation (CCW) was present near the maximum lift timing of the intake valves. The peak TKE at the intake stroke was present at -260° BTDC, with WOT (wide open throttle) and it was quite similar at 1000 and 1500 RPM. As expected, at 25% throttle position the TKE was less compared to the WOT case. The absolute value of TR, was much higher for the tumble plane comparing to the other measurement planes, both at 1000 and 1500RPM.
Tsiogkas, Vasileios D., Chraniotis, Anastasios, Kolokotronis, Dimitrios, Tourlidakis, Antonios
Large Eddy Simulations and Tracer-LIF Diagnostics of Wall Film Dynamics in an Optically Accessible GDI Research Engine2019-24-01319/9/2019
Large Eddy Simulations (LES) and tracer-based Laser-Induced Fluorescence (LIF) measurements were performed to study the dynamics of fuel wall-films on the piston top of an optically accessible, four-valve pent-roof GDI research engine for a total of eight operating conditions. Starting from a reference point, the systematic variations include changes in engine speed (600; 1,200 and 2,000 RPM) and load (1000 and 500 mbar intake pressure); concerning the fuel path the Start Of Injection (SOI=360°, 390° and 420° CA after gas exchange TDC) as well as the injection pressure (10, 20 and 35 MPa) were varied. For each condition, 40 experimental images were acquired phase-locked at 10° CA intervals after SOI, showing the wall-film dynamics in terms of spatial extent, thickness and temperature. The simulation framework was developed as follows: first, the spray model was calibrated using spray morphology evolution data of the same injector, characterized in a constant volume spray chamber by high-speed shadow imaging. In a second step, the wall impingement and film models were calibrated using the reference condition. With the model constants now fixed, simulations were run for the remaining operating points and results were compared with the experimental data. The simulations captured all trends observed experimentally, with good quantitative in the transient films’ spatial extents and thicknesses.
Frapolli, Nicolò, Boulouchos, Konstantinos, Wright, Yuri M., Geiler, Jan N., Manz, Andreas, Kaiser, Sebastian A.
Deployable Emergency Shutoff Device Blocks High-Velocity Fluid FlowsTBMG-349318/1/2019
NASA's Marshall Space Flight Center has developed a device and method for blocking the flow of fluid from an open pipe. The device plugs, controls, and meters the flow of gases and liquids. Anchored with friction fittings, spikes, or explosively activated fasteners, the device is well-suited for harsh environments and high fluid velocities and pressures. With the addition of instrumentation, it can also be used as a variable-area flow metering valve that can be set based upon flow conditions. With robotic additions, it can be configured to crawl into a pipe and then anchor and activate itself to block or control fluid flow.
Optimizing Cooling Fan Power Consumption for Improving Diesel Engine Fuel Efficiency Using CFD Technique03-12-04-00246/11/2019
Fan cooling system of an air-cooled diesel engine is optimized using 3D CFD numerical simulation approach. The main objective of this article is to increase engine fuel efficiency by reducing fan power consumption. It is achieved by optimizing airflow rates and flow distribution over the engine surfaces to keep the maximum temperature of engine oil and engine surfaces well within the lubrication and material limit, respectively, at the expense of lower fan power. Based on basic fan laws, a bigger fan consumes lesser power for the same airflow rate as compared to a smaller fan, provided both fans have similar efficiency. Flow analysis is also conducted with the engine head and block modeled as solid medium and fan cooling system as fluid domain. Reynolds-averaged Navier-Stokes turbulence (RANS) equations were solved to get the flow field inside the cooling system and on the engine liner fins. The Moving Reference Frame approach was used for simulating the rotation of a fan. Cowl geometry was modified for providing better guidance to flow over engine surfaces and to get maximum utilization of cooling capacity of flowing air. Basic fan parameters like diameter, blade shape, and number of blades were altered to increase the flow rate and reduce fan power consumption. Engine surface temperature is compared between existing and recommended design modified on actual engine test bed. The final recommended design leads to a 3% improvement in engine fuel efficiency, i.e., engine fan power consumption reduction. It is achieved with comparable engine surface temperature.
Nain, Ajay
Acoustic Effects of Lightweighting in a Sport Utility Vehicle2019-01-15066/5/2019
Weight reduction is a significant concern for automotive manufacturers, and is often achieved by removing as much mass as is safe from the structure of the vehicle. This has a negative effect on the interior acoustics, which has become more and more of an issue as technology has advanced and people expect to be able to do business and consume media in their vehicles. Traditional acoustic treatment tends to be very heavy, which eliminates some of the weight savings. Recently a vehicle study was performed to determine if the current production sound package in a highly-rated sport utility vehicle could be maintained or improved while reducing the weight. This paper presents the results of that study. The study focused on road noise transmitted through the floor (carpet, rear wheelhouse inner and trunk insulation) and engine noise transmitted through the dash (dash inner). Testing was performed both at the vehicle level on the road and at the component level in the laboratory. It was found that the lightweight sound package was highly effective against road noise, but less effective against engine noise. Additional evaluation was performed to determine if underbody treatment would improve the performance, and it was found the addition of absorption to the underbody of the car helps with road noise, but less so with engine noise. Ultimately, the lightweight parts, working together as a system, provided sound absorption in the frequency range of interest while still providing the necessary sound transmission loss along the noise paths.
Frey, Andrea Lynne
Development and Application of an Objective Metric for Transient Engine Clatter Noise2019-01-15196/5/2019
Several powertrain noise phenomena have been studied over the years. Sound quality metrics, like loudness, sharpness, modulation, and tonality, among others, have been developed to characterize powertrain noises. While these readily available metrics work well on steady state and some transient noises, they do not correlate directly with subjective impressions. Moreover, it is difficult to assign a meaningful single rating for time varying noises that may also be associated with simultaneous variations in frequency content. This paper summarizes the process of creating a vehicle level objective metric and its application to blind noise samples to verify correlation with subjective impressions, particularly in association with clatter noise at moderate engine speeds (2000-3500 rpm) with light to moderate throttle tip-ins. The main results include a single number rating and a rating curve as a function of engine speed useful for comparative NVH assessments of multiple vehicles or of multiple hardware iterations on a development vehicle with objectionable clatter content. The latter application is particularly useful since it gives correct feedback to an uninitiated engineer about the hardware changes he or she is proposing. Further this could help in data driven decision making during cost versus benefit assessments.
Parbat, Aniket, Charan, Anil
Performance Testing and Analysis of Multi-Channel Active Control System for Vehicle Interior Noise Using Adaptive Notch Filter2019-01-15676/5/2019
It is considered that slow convergence speed and large calculation amount of commonly used adaptive algorithm in the active control system for vehicle interior noise yield noise reduction performance and hardware requirements problems. In this paper, a 4-channel active control of vehicle interior noise based on adaptive notch filter is established, and road test is carried out to test and analyze the performance of the control system. Firstly, the general mathematic model of the multi-channel active control system based on adaptive notch filter is established. The computational complexity of the algorithm is analyzed and compared with that of the FXLMS algorithm. Secondly, a hardware-in-the-loop test bench based on multi-channel adaptive notch filter is set up, to measure the noise reduction performance of ANC system under various working conditions. Finally, the typical test conditions are designed to test the system noise reduction performance, and the road test is carried out and result is analyzed.
Zhang, Lijun, Zhang, Xiyu, Meng, Dejian
Experimental Investigation on Gear Rattle Noise Reduction in Passenger Car2019-01-15616/5/2019
Gear rattle noise reduction inside the passenger cabin is one of the major challenges for customer comfort enhancement. Therefore, it becomes a prime target during transmission design and development. Gear rattle is generated due to meshing teeth collision of free gears, which is caused due to torsional vibration of engine transferred through clutch. Vibrations are generated due to free gears teeth impact and are transferred to shaft, bearings and transmission housing. The sound absorption and structural vibration of transmission housing was optimized by changing the geometrical features of the transmission housing that affects radiated noise. Experimental approach for gear rattle noise reduction through transmission housing modification is described in this paper. Moreover, CAE method is also incorporated with the experiments for optimization of future vehicle transmission system designs.
Khare, Devendra Kumar, Vaishya, Abhishek Lakhanlal, Pujara, Archan Sunibhai, Krishna, Radhe, Satpathy, Kingshuk, Choudhary, Ved Prakash, Pandey, Anant
Modeling of Micro-Perforated Heat Baffle2019-01-15826/5/2019
Classical porous materials are used throughout the automobile with usually good success but there are limitations to their performance in areas where there are adverse environments. An example of this is the transmission tunnel section under the automobile, where there exist high air flow velocities and temperatures which will lead to quick deterioration of the material. Micro-Perforated Heat Baffles (MPHB) are showing success in the heating, ventilating, and air conditioning industry, and therefore there is an effort in applying MPHB extensively in the automotive field. The question with regards to which micro-perforation pattern gives the best performance plus where and how much should be allocated in the automobile still remains. This paper shows how to address these issues by applying Hybrid Statistical Energy Analysis (HSEA) technology. An expression for the Absorption Coefficient (AC) which incorporates the micro-perforation pattern is explained. This equation models the absorption of sound due to friction losses in the holes. Thereafter calculations for flat sample AC are completed and good correlation with experimental data is shown. Flat sample AC is necessary to know but by itself it does not answer the important question whether SPL suppression is being realized on a real car and how this is addressed without building multiple prototypes. Thus, the paper emphasizes the importance of having a HSEA model and how with this model an noise and vibration specialist can run multiple MPHB concepts. This paper shows this capability by applying MPHB to cover the transmission tunnel under the automobile and the calculated SPL under different input modes such as road noise and engine noise.
Teagle-Hernandez, Allen, Ide, Fumihiko, Ichikawa, Shota, Yabe, Kengo, Matsuda, Takehisa
Global Tests and Specifications for Automotive Engine OilsJ2227_201905 (Current)5/8/2019
This SAE Information Report lists engine and laboratory tests for service fill engine oils which are associated with specifications and classifications established outside of SAE J304 and SAE J183. These specifications and classifications include those developed prior to April 1, 2017, by international technical societies, as well as individual original equipment manufacturers. The information contained within this report applies to engine oils utilized in gasoline- and diesel-powered automotive vehicles.
Fuels and Lubricants TC 1 Engine Lubrication
Thermal Management of a Hybrid Vehicle Using a Heat Pump2019-01-05024/2/2019
This paper presents the thermal management of a hybrid vehicle (HV) using a heat pump system in cold weather. One advantage of an HV is the high efficiency of the vehicle system provided by the coupling and optimal control of an electric motor and an engine. However, in a conventional HV, fuel economy degradation is observed in cold weather because delivering heat to the passenger cabin using the engine results in a reduced efficiency of the vehicle system. In this study, a heat pump, combined with an engine, was used for thermal management to decrease fuel economy degradation. The heat pump is equipped with an electrically driven compressor that pumps ambient heat into a water-cooled condenser. The heat generated by the engine and the heat pump is delivered to the engine and the passenger cabin because the engine needs to warm up quickly to reduce emissions and the cabin needs heat to provide thermal comfort. To control the heat flow from the engine and the heat pump, switching between coolant circuits was used. An optimal way to control the engine and the heat pump to minimize the fuel consumption was found. To this end, a 1-D thermal vehicle model was used for optimization, and the fuel economy of the optimized system was measured on a prototype vehicle. Compared to a conventional HV, the fuel economy of the optimized system improved by 10%.
Okamoto, Kei, Aikawa, Hidefumi, Ohmikawa, Minoru, Hayashi, Kunihiko
A Research on Vehicle Gearbox Whine Based on Multi-Physics Coupling Simulation and Psychoacoustics2019-01-07794/2/2019
Vehicle gearbox whine is a common NVH problem which may directly cause complains from passengers on the quality and performance of vehicle. In order to efficiently and fundamentally control the whine phenomenon, this work first studied the characteristics and mechanisms of the gearbox vibration and noise. The study results revealed that the transmission error of gear was the excitation source of gearbox vibration, and the ambient air was the main transfer path of radiation noise. Then a multi-physics coupling simulation model was built to reveal the interactions among gear, housing and ambient air. This model could also predict the characteristics of the sound field near the passenger’s ear. To take account the psychoacoustic property of human auditory system, this work applied a quality index called tonality to evaluate the severity of gearbox whine. This paper also describes a case study to verify the accuracy and availability of the simulation model. In this case, the whine phenomenon of a practical gearbox was simulated with the proposed model first, and then an optimization on the micro geometry of gear was applied to decrease the noise level to an acceptable level. The main significance of this work is to propose an integrated and effective approach to control the gearbox whine. The indicative conclusions of this work could be referred by NVH engineers in the early phase of vehicle gearbox development.
Tang, Sicheng, Xu, Yong
Evaluation of Gasoline Additive Packages to Assess Their Ability to Clean Up Intake Valve Deposits in Automotive Engines2019-01-02614/2/2019
The majority of passenger car and light-duty trucks, especially in North America, operate using port-fuel injection (PFI) engines. In PFI engines, the fuel is injected onto the intake valves and then pulled into the combustion chamber during the intake stroke. Components of the fuel are unstable in this environment and form deposits on the upstream face of the intake valve. These deposits have been found to affect a vehicle’s drivability, emissions and engine performance. Therefore, it is critical for the gasoline to be blended with additives containing detergents capable of removing the harmful intake valve deposits (IVDs). Established standards are available to measure the propensity of IVD formation, for example the ASTM D6201 engine test and ASTM D5500 vehicle test. However, rigorous testing conducted in a modern fleet of vehicles in a statistically robust design can provide greater insight into the actual performance of modern PFI engines with available gasoline additive packages. In this study, an optimized mileage accumulation protocol was used to assess the performance of new experimental gasoline additive packages in removing the IVDs in a fleet of vehicles typical of engines and vehicles available in the North American vehicle parc. The performance of a gasoline additive package, both at lower and higher additive treat-rates, was compared to that of a commercial additive package at EPA-approved lowest additive concentration (LAC). Based on three decades of expertise, the testing protocol was optimized to use fewer vehicles and shorter mileage accumulation than previously required for the same statistical confidence. It was observed that the tested experimental gasoline additive packages demonstrated a statistically higher cleanup at both treat-rates compared to the commercial LAC additive package. This rigorous statistically-robust test protocol can be used to assess candidate fuel additive packages for the North American gasoline market.
Raj Mohan, Vivek Raja, Nelson, Edward, Reitz, Jannik, Kensler, Jennifer, Gauba, Varun, Hinojosa, Matthew, Shoffner, Brent
Intake and Exhaust Ports Design for Tumble and Mass Flow Rate Improvements in Gasoline Engine2019-01-07634/2/2019
In recent years, world-wide automotive manufacturers have been continuously working in the research of suitable technical solutions to meet upcoming stringent carbon dioxide (CO2) emission targets, as defined by international regulatory authorities. Many technologies have been already developed, or are currently under study, to meet legislated targets. In-line with above objective, the enhancement of turbulence intensity inside the combustion chamber has a significant importance which contributes to accelerating the burning rate, to increase the thermal efficiency and to reduce the cyclic variability [9]. Turbulence generation is mainly achieved during the intake stroke which is strictly affected by the intake port geometry, orientation and to certain extends by combustion chamber masking. Conservation of turbulence intensity till 700~720 crank angle (CA) is achieved by optimized shape of combustion chamber geometry and piston bowl shape. High exhaust port flow also contributes to overall engine efficiency by reduction of residual gas fraction (RGF); this enables high compression ratio (CR) operation by reducing in compression end temperature (CET). In this work, different geometries of the intake port have been designed and analyzed by means of three dimensional (3D) computational fluid dynamics (CFD) simulations, to foresee the in-cylinder tumble motion development during intake stroke. Final design is manufactured and tested on flow bench. 45% tumble improvement has been attained over base design without loss of mass flow rate (MFR). Similarly exhaust port has also been re-designed by performing numbers of iterations to enhance exhaust port flow and velocity by steady state CFD iterations. Similar to intake port, actual flow measurement is also performed on exhaust port and 36% increase in MFR performance is gained.
Singh, Amandeep, Poonia, Sanjay, Jalan, Ankit, Singh, Jaspreet, Kumar, Narinder
Native Over-Expanded Engine Based on a Planetary Crankshaft with Enhanced Balancing2019-01-11944/2/2019
Over-expansion is one of the promising strategies for improving Internal combustion engine (ICE) efficiency and emissions. It can be implemented by using an unconventional crankshaft. These mechanisms have mass production potential and acceptable friction losses, but also a complex kinematic and dynamic behaviour. This paper proposes such a crank design, a small planetary hypotrochoid over-expanded single cylinder engine - UMotor - and compares it to equivalent conventional ICEs with similar intake or expansion strokes. A suitable crankshaft counter weight geometry was determined in order to minimize the overall reaction forces. The mass balancing studies were conducted via a dynamic motion analysis of the crank drive, including a Fast Fourier Transform (FFT) frequency analysis. For the tested engine speeds, the UMotor average and peak magnitude reaction forces proved to be similar to those generated in the conventional engines for intermediate and high engine speeds. Also, the UMotor displayed fewer high frequency harmonics, indicating a lower structural disturbance of the chassis of a vehicle equipped with one of these engines.
Capela, Guilherme, Costa, Tiago J., Meireles, José, Martins, Jorge, Brito, F. P.
Analytical Evaluation of Engine and Vehicle Hardware Effects on Vehicle Response2019-01-12834/2/2019
As the proliferation of downsized boosted engines continues, it becomes increasingly important to understand how engine and vehicle hardware impact vehicle transient response. Several different methodologies can be used to understand hardware impacts, such as vehicle testing, 0-D vehicle models, and constant engine speed load steps. The next evolution of predicting vehicle transient response is to transition to a system level vehicle analysis by coupling a detailed engine model, utilizing crank angle resolved calculations, with a simple vehicle model. This allows for the evaluation of engine and vehicle hardware effects on vehicle acceleration and the rate of change of vehicle acceleration, or jerk, and the tradeoffs that can be made between the hardware in early program development. By comparing this system level vehicle model to the different methodologies, it can be shown that a system level vehicle analysis allows for higher fidelity evaluations of vehicle transient response. This contributes to greater understanding of hardware effects on vehicle transient response and allows for improved optimization of vehicle level response, performance and fuel economy.
Raftopoulos, Andrew Arthur, Morris, Ronald Robert, Weber, Lukas
Development of Compensation Logic for EPS in Limit Cornering Condition2019-01-14223/25/2019
This paper proposes steering compensation logic of Electric Power Steering (EPS) system in limit cornering condition. Steering wheel torque is decided by relationships between internal forces and external forces. The internal forces are steering frictions and assist force. The external forces are transferred from tire forces through kingpin axis and steering system. Kingpin moments are analyzed by using vector analysis and tire model. Relations of these forces are defined and used to explain steering disturbance by comparing simulation results and measurement data. Using these relationships, the proposed compensation logic is designed. This logic is verified by simulation models and validated in proto type vehicle.
Lee, Hanseung, Lee, Jae Kil
Fermi National Accelerator LaboratoryTBMG-339423/1/2019
Since 1967, Fermi National Accelerator Laboratory (Fermilab) has been the United States’ premier particle physics laboratory, working on the world's most advanced particle accelerators and digging down to the smallest building blocks of matter.
Research Explores Internal Flow Behavior in Additive Manufacturing, Welding of MetalsTBMG-340273/1/2019
Arc welding and additive manufacturing are hugely important for creating large metal components relatively inexpensively and quickly. New research by a team at the University of Leicester, Delft University of Technology, Diamond Light Source, University College Dublin, and TATA Steel Research UK has shown how to optimize this process to improve efficiency and cost. A paper detailing the findings was recently published in Nature Communications. The research explores the internal flow behavior in additive manufacturing of metals and arc welding — the most widely used welding process in modern manufacturing. It focused on examining the melt pools that are created during the welding process.
Diagnosis and Elimination of Vehicle Lateral Shake in Passenger Car through Modification of Driveshaft Joints and Engine Mount System2019-26-02141/9/2019
Vehicle lateral shake during take-off is sensitively felt by customers when the vehicle is driven at a low speed under drive away acceleration. The take-off shudder is complained by customers during 1st and 2nd gear take off. Under an engine torque and half shaft angle, the drive-away shudder usually occurs during acceleration to a specific low speed at 1200 to 1600 engine rpm, which makes the vehicle shake severely. A thorough investigation with possible design optimization of mounting system, drive shaft joint and lubrication is done to reduce the lateral vibration. This paper focuses on a passenger car, the take-off shudder of which occurs at a speed between 20 km/h and 30 km/h. The test vehicle is a monocoque construction with front wheel drive east west engine. Vehicle lateral shake is observed during the low gear power train run up in Wide Open Throttle (WOT) condition. The lateral shake is felt predominantly on the front half of the vehicle which is easily perceivable by passenger. The paper discusses the measurement and analysis procedures to identify the root cause of shudder. Different modifications are tried out based on the analysis and an optimum solution is selected. The selected modification does not have any adverse effect on other Noise Vibration and Harshness (NVH) attributes.
Hazra, Sandip, Kharade, Ajit, Thakur, Sunil
1D Simulation Accuracy Enhancement for Predicting Powertrain Cooling System Performance2019-26-02981/9/2019
In today’s competitive scenario, the automotive product life cycle has drastically reduced and all Auto OEM’s are coming up with their updated products with lesser development time. These frequent product upgrades are possible due to use of various digital tools during product design and development. Design and optimization of engine coolpack (powertrain cooling unit) to attain engine cooling performance is one of the important parameter during vehicle development or upgrade. Hence, to keep control over development cost and time of delivery, quick and accurate digital validation capability like one dimensional (1D) simulation is the need of the hour. To predict the powertrain cooling (PTC) performance at vehicle concept stage, when physical prototypes are not available, airflow data from similar developed platforms is considered as an input for 1D simulation. As the vehicle program matures and the 3D CFD airflow simulation results become available as an input, 1D simulation accuracy of 87~90% can be achieved. However, even at this stage, 3D CFD airflow simulation results are provided under the assumption of isothermal condition. Due to this assumption, the effect of heat rejection from upstream components in the coolpack (consisting of condenser, charge air cooler, radiator and fan) on airflow is not taken into account. In addition, the proximity of the coolpack to the engine may result in hot air recirculation. Additionally, the heat rejection and coolant flow rate used for simulation measured at engine test bed differ from that experienced in actual vehicle. This paper addresses the effect of heat rejection from upstream components on the density of air as it moves across the coolpack, the effect of hot air recirculation and the correction factors required in inputs obtained from engine test bed. The methodology and model developed in this work have been validated against real world physical test data. Using this proposed methodology simulation prediction with an accuracy of 95~97% is obtained.
Jaybhay, Sambhaji, Singhal, Shubham, Dubey, Ritambhara Raj, Kapoor, Sangeet
Prediction and Resolution of Vehicle In-Cab Noise due to Powertrain Induced Excitations2019-26-01771/9/2019
Vehicle NVH is one of the critical performance quality parameter and it consists of vibration levels at tactile points and noise levels at ear locations for different vehicle running conditions. There are many sources of noise and vibration in a vehicle, and powertrain is one of the main source. Therefore, it is important to understand and resolve powertrain induced noise and vibration issues at early design stage with efficient simulation techniques. The work presented here deals with the use of systematic CAE approach for prediction and resolution of structure borne in-cab noise due to powertrain excitations. During NVH testing of SUV vehicle, boom noise is observed at low frequency. Detailed full vehicle level simulation model consisting of vibro-acoustic trimmed BIW, front and rear suspension, and driveline with powertrain modal model is built. Powertrain dynamic loads due to inertia and combustion pressure are applied at powertrain C.G. and in-cab noise at driver ear location (DEL) is predicted. Predicted in-cab noise shows good correlation with measured 2EO noise. Root cause analysis shows that front sub-frame has vibration mode in the frequency range of issue. Based on simulation, conceptual modification of rigid plate between sub-frame and vehicle body is suggested and gives significant improvement in vehicle in-cab noise when tested. Using simulation approach, other feasible design solutions are worked out.
Lakshe, Shailesh, Chittilla, Kishore, Raut, Manoj, Titave, Uttam
Sound Package Development for a Vehicle in Static Condition2019-26-01741/9/2019
Sound package material selection plays a vital role in maintaining passenger comfort by suppressing noise inside cabin. Sound package development in static condition minimizes the extrinsic variables which influence the measurements. The consideration of static condition favors simulation and its correlation with test data. Once correlation is achieved, simulation inputs are used for further optimization and improvements. Noise control can be done in three levels by working either on source, path or receiver. In automobiles, there are many sources of noise such as engine, tire and wind. This topic deals with quantification of various transfer paths between source and receiver location using Power Based Noise Reduction (PBNR) method. This methodology is used in both simulation and testing along with its overall scope for improvement. It is best to quantify path strength in terms of energy levels instead of mere amplitude due to its independency on external test conditions. In this paper, High frequency Statistical Energy Analysis (SEA) is used for front loading. PBNR was predicted between noise sources (engine, tires etc.) and receiver seating locations for frequency range of 200 - 6300 Hz. In addition, PBNR is measured using Dodecahedral Source (DDS) and PU probe and correlated with simulation values. The critical paths are identified based on PBNR data and design modifications are proposed to meet the target levels. The development activity was traced from baseline vehicle to modified one and improvement in PBNR level by 2-5 dB throughout the high frequency (>200Hz) range was achieved in static condition and the similar improvement reflected in dynamic condition as well. In 3rd gear, Wide Open Throttle (WOT) driving condition, improvement of 15% in Articulation Index (AI) is observed.
Tulesh, Kumar, Anerao, Nitesh, Deshpande, Samar, Natarajan, Jayakumar, R, Prasath
Two Stroke Gasoline Direct Injection Strategy Optimization Using 1D and 3D Analysis Tool2019-26-03111/9/2019
A two-stroke engine is a type of internal combustion (IC) engine that completes the power cycle in one crankshaft revolution, which is half the number in comparison with four-stroke engine. Spark Ignition (SI) two-stroke engines are commonly found in the small power tools such as chain saw and scooter. While Compression Ignition (CI) engines are commonly used in large machines such as marine propulsion and electricity generator. Two-stroke engines have several inherent advantages over four stroke engines such as simple and compact design, high power-to-weight ratio, lower NOx emissions etc. The piston of the two-stroke reciprocating engine takes over valve functions in order to obtain a power stroke for each revolution of the crankshaft. The valve overlap period in case of two stroke SI engines is greater than four stroke SI engines; this loss of fresh fuel is called short-circuiting [1]. This accounts for major source of hydro-carbon (HC) emissions and increased specific fuel consumption in two stroke SI engines. Independent fuel supply system could easily reduce inherent disadvantages of higher hydrocarbon emissions and low fuel economy. The most essential issue to be tended to by a conventional two stroke SI Engines is the consistence with stringent emission standards, which relies upon the combustion pattern and the scavenging efficiency Gasoline direct injection is the only practical solution for emissions, generated by short-circuiting as well as incomplete combustion. The impact of injection variables on the performance parameter along with combustion, its extend feasibility and complexity are reviewed in present work. The injection variables include injection timing (start of injection), injection pressure, injector axis and injection pattern (wall guided/spray guided/air guided). The review comes up with the need of optimization for mixture formation to reduce in-cylinder wall wetting, increase combustion stability and performance parameters in GDI engine. The current study reviews the development process, assisted by 1D & 3D CFD analysis tool. Engine performance parameters have been predicted using well-established commercial software AVL Boost, while 3D CFD analysis have been carried out using ANSYS Fluent 18.0. The simulated 1D model and 3D CFD model shows good co-relationship with the experimental results of baseline two stroke carburetted engine tested at wide open throttle condition. CFD based optimization is performed to choose injection strategy for maximizing the engine power output and ensuring complete combustion prior to exhaust port opening. The improvement in results are due to inherent advantages of two stroke engines along with the capability to inject fuel post exhaust port closing and charge stratification using gasoline direct injection system.
Chavan, Yuvraj, Sewatkar, Chandrashekar
Design, Simulation & Optimization of an Air Intake System to Reduce Induction Noise2019-26-01911/9/2019
Air intake system (AIS) plays a major role in reducing the noise level in passenger car compartment, which has become an important requirement due to increasing customer expectation for better in cab noise. The ideal air intake system design should have minimum possible noise at snorkel entry point which ultimately contributes in cabin noise. There are different techniques that are implemented for an air intake system noise reduction e.g. choosing proper location of air entry suction point in engine bay compartment, suitable design for air filter box (volume), duct designs etc. Further design improvement are possible with an addition of tuned resonators in the system. An addition of resonator have major effect seen in reducing air induction noise and to meet target Sound Pressure Levels (SPL). But at the same time, selecting the correct type of resonator, its position & volume, frequency/s band at which resonator is tuned are important parameters. The work presented here describes and compares the simulation results (GT POWER) with the measured SPL levels at different rpm range with different resonator types for Utility Vehicle (UV) as below, a Air intake system without resonator. b Multi-band resonator: resonator tuned for larger range of frequency band and requires more packaging volume. c Helmholtz resonator: resonator tuned for single frequency (for certain rpm at which peak observed) & requires less packaging volume. Based on the correlation developed between simulation and test results, the simulation models are useful for further refinement and proper selection of final optimum hardware. These simulation models are also further useful for future programs at design stage itself.
Patil, Ujwal, Rahane, Dnyanesh
Paving the Way: An Accelerator on a MicrochipTBMG-335611/1/2019
Particle accelerators are usually large and costly, but that will soon change if researchers have their way. The Accelerator on a Chip International Program (AChIP), funded by the Gordon and Betty Moore Foundation in the United States, aims to create an electron accelerator on a silicon chip. The fundamental idea is to replace accelerator structures made of metal with glass or silicon, and to use a laser instead of a microwave generator as an energy source. Due to glass's higher electric field load capacity, the acceleration rate can be increased and thus the same amount of energy can be transmitted to the particles within a shorter space, making the accelerator shorter by a factor of approximately 10 than traditional accelerators delivering the same energy.
Injury Risk Curves for the Human Cervical Spine from Inferior-to-Superior Loading2018-22-000611/12/2018
Cervical spine injuries can occur in military scenarios from events such as underbody blast events. Such scenarios impart inferior-to-superior loads to the spine. The objective of this study is to develop human injury risk curves (IRCs) under this loading mode using Post Mortem Human Surrogates (PMHS). Twenty-five PMHS head-neck complexes were obtained, screened for pre-existing trauma, bone densities were determined, pre-tests radiological images were taken, fixed in polymethylmethacrylate at the T2-T3 level, a load cell was attached to the distal end of the preparation, positioned end on custom vertical accelerator device based on the military-seating posture, donned with a combat helmet, and impacted at the base. Posttest images were obtained, and gross dissection was done to confirm injuries to all specimens. Axial and resultant forces at the cervico-thoracic joint was used to develop the IRCs using survival analysis. Data were censored into left, interval, and uncensored observations. The Brier score metric was used to rank the variables. The optimal metric describing the underlying response to injury was associated with the axial force, ranking slightly greater than the resultant force, both with BMD covariates. The results from the survival analysis indicated all IRCs are in the “fair” to “good” category, at all risk levels. The BMD was found to be a significant covariate that best describes the response of the helmeted head-neck specimens to injury. The present experimental protocol and IRCs can be used to conduct additional tests, matched-pair tests with the WIAMan and/or other devices to obtain injury assessment risk curves (IARCs) and injury assessment risk values (IARVs) to predict injury in crash environments, and these data can also be used for validating component-based head-neck and human body computational models.
Yoganandan, Narayan, Chirvi, Sajal, Pintar, Frank A., Banerjee, Anjishnu, Voo, Liming
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