Browse Topic: Turbochargers

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Acoustic Assessment in a Small Displacement Diesel Engine2014-32-01291/30/2026
In the last years, the increasing concern for the environmental issues of IC engines has promoted the development of new strategies capable of reducing both pollutant emissions in atmosphere and noise radiation. Engines can produce different types of noise: 1) aerodynamic noise due to intake and exhaust systems and 2) surface radiated noise. Identification and analysis of noise sources are essential to evaluate the individual contribution (injection, combustion, piston slap, turbocharger, oil pump, valves) to the overall noise with the aim of selecting appropriate control strategies. Previous paper focused on the combustion related noise emission. The research activity aimed at diagnosing and controlling the combustion process via acoustic measurements. The optimal placement of the microphone was selected, where the signal was strongly correlated to the in-cylinder pressure development during the combustion process. Analysis and processing of the sound emission allowed the acoustic
Chiatti, Giancarlo, Recco, Erasmo, Chiavola, Ornella, Conforto, Silvia
Evaluation of Intercooler Effectiveness with No Fan, Single Fan, and Dual Fan: A Simulation and Experimental Study2026-26-05791/16/2026
Turbochargers play a crucial role in modern engines by increasing power output and fuel efficiency through intake air compression, thereby improving volumetric efficiency by allowing more air mass into the combustion chamber. However, this process also raises the intake air temperature, which can reduce charge density, lead to detonation, and create emissions challenges-such as smoke limits in diesel engines and knock in gasoline spark-ignited (GSL) engines. To mitigate this, intercoolers are used to cool the compressed air. Due to packaging constraints, intercoolers are typically long and boxy, limiting their effectiveness, especially at low vehicle speeds where ram air flow is minimal. This study investigates the use of auxiliary fans to enhance intercooler performance. Two methodologies were adopted: 1D simulation using GT-Suite and experimental testing on a vehicle under different fan configurations-no fan, single fan, and dual fans (positioned near the intercooler inlet and outlet
PATRA, SOMNATH, HIBARE, NIKHIL, Ganesan, Thanigaivel, Gharte, Jignesh Rajendra
Simulation driven design of robust Crank-train systems for elevated In-cylinder combustion pressure2026-26-04001/16/2026
The need for increased in-cylinder pressure to meet the higher engine rating and stringent emissions norms requires special attention on the Main moving components torsional behaviour and the bearing performance. The work presented in this paper utilizes the 1D and 3D simulation potential of AVL EXCITE for the assessment of design changes required in Crank-Train system for the increased in-cylinder pressure from 170bar to 220bar. The key feature of the executed work was that all the design changes were accommodated with minimal changes in packaging / layout interfaces. The given work was executed on 6-Cylinder Turbocharged In-cylinder with Type V valve-train configurations. Initial brain storming & 0d calculation helped in understanding the design optimization required in each and every crank-train parts. Considering the guidelines available in terms of L/d ratio for the bearing, connecting rod length, the overall linkage specification was set up for starting with design work for
Khandelwal, Meha
EVALUATION OF DRIVELINE NVH PERFORMANCE USING LINEAR DYNAMIC FINITE ELEMENT SIMULATION2026-26-03221/16/2026
Automotive driveline design plays an important role in the NVH characteristics of the overall vehicle. Driveline systems are an integral part of delivering torque from the engine/transmission to the tires which propel the vehicle and drivelines often experience a wide frequency of excitation which poses unique NVH challenges. With the increasing trend in the automotive industry to introduce turbocharged engines with fewer cylinders while delivering the same torque / power, the driveline systems are excited with increased lower frequency torsional vibration in addition to other vibrations transmitted from powertrain and road. In this paper, we address the key design consideration for developing an optimal driveline system with consideration to NVH while keeping durability and other functional requirements in perspective. We consider the example of a front wheel drive-based vehicle architecture with independent suspension. The effect of fundamental prop shaft frequency to determine
JOSHI, ATUL KAMALAKARRAO, Subramanian, MANOJ
Key Parameters for Turbocharger selection & experimental validation for Off-Highway Applications2026-26-01041/16/2026
Customers in off-highway industry are increasingly seeking high-performance capabilities for their tractors due to increasing penetration of mechanisation and labour scarcity. One effective solution to achieve enhanced performance is turbocharging of engines, while meeting emission and highly dynamic transient response of tractor field applications. The process of selecting and validating a suitable turbocharger for tractor field application suitability is significantly time and resources consuming activity due to extensive testbed and field trials. This study focuses on the selection of turbocharger for tractor engines through analytical calculations to freeze key parameters like lambda, boost pressure ratio & temperature within boundaries of exhaust temperature and turbo efficiency maps to deliver best field transient performance and fuel consumption. The selected parameters are further validated under real-world transient operating conditions, involving tractors and their implements
RAWAT, SAURABH, KUMAR, HARISH KUMAR, Singh, Amarinder, Singh, Sachleen, Dogra, DaljitSingh
Engine Management System Strategies for Mitigating Dual Mass Flywheel Resonance in Gasoline Powertrains2026-26-00521/16/2026
In today's fast paced and competitive automotive market meeting the customers expectations is the key to any OEM. This has led to development of downsized high performance engines with refinement as an important deliverable. However developing such high output engines do come with challenges of refinement, especially higher torsional vibrations leading to transmission noise issues. Hence, it becomes important to isolate the transmission system from these high torsional vibration input. To address this, one of the most common method is to adopt Dual Mass flywheel (DMF) as this component dampens torsional vibrations and isolates the transmission unit from the same. While Dual Mass Flywheel assemblies do great job in protecting the transmission units by not allowing the oscillations to pass through them, they do have their own natural resonance frequency band close to the engine idle (low) engine speeds, which must be avoided for a continuous operation otherwise it may lead to Dual Mass
Raiker, Rajan, viswanatha, Hosur C, Jadhav, Aashish, Jain, Ojase, Jadhav, Marisha
Improving Cold Start and Transient Performance of Medium BMEP CEV Stage V Engines at Low Ambient Temperature and Pressure2026-26-01421/16/2026
Meeting the stringent emissions norms of CEV stage V for medium BMEP engines, CI engines present significant challenges, particularly concerning cold startability. Low ambient temperatures and pressures intensify the cold start difficulties which are characterized by prolonged cranking, incidences of misfiring, compromised transient response and overall engine performance. This paper highlights the strategies and technologies employed to enhance cold start and transient performance of medium BMEP engines under such demanding environmental conditions. Investigations were conducted up to an altitude of 4500m and ambient temperatures as low as-20°C, utilizing only air heater at intake manifold as the sole cold start aid. This cost effective approach is integrated with an optimized combustion chamber design, along with minimal pilot injection timing and quantity to facilitate smooth ignition and stable combustion during cold start. The paper also explore the techniques to improve the
Saxena, Harshit, Lokare, Prasad, Santhosh, Ajith, Gandhi, Naresh, Shinde, Prashant
Optimization of a Positive Displacement Type Supercharger Using Response Surface Modeling (RSM)2026-26-04291/16/2026
Air suction in a naturally aspirated engine is a crucial influencing parameter to dictate the specific fuel consumption and emissions. For a multi-cylinder engine, a turbocharger can well address this issue. However, in a single or two-cylinder engine, the usage of turbocharger is not recommended, due to the lack of availability of continuous exhaust energy pulses. A supercharger solution comes handy in this regard for a single or two-cylinder engine. In this exercise, we explore the possibility of the usage of a positive displacement type supercharger, to enhance the air flow rate of a single cylinder, naturally aspirated, diesel engine for genset application, operating at 1500 rpm. The supercharger parametric 3D CAD model was prepared in Creo, with (a) Generating radius, (b) depth of blower and (c) clearance between lobes & lobe and casing, being treated as three parameters. The optimum supercharger design was expected to (a) generate a boost pressure of minimum 0.4 bar (gauge), (b
Satre, Santosh Dadasaheb, Mukherjee, Nalini, Rajput, Surendra, Nene, Devendra
A mechanism to maintain negative crankcase pressure in a turbocharged gas engine to meet Euro-VI emission regulation and to reduce oil consumption.2024-26-01451/16/2024
Emissions regulation continually drives the automotive industry to innovate and develop. This pushes to introduce mechanism to maintain negative crankcase pressure in gas engine to meet this changing regulation. The way a turbocharger is used, to meet engine performance, can impact the pressure balance over the compressor and turbine end seals. This pressure difference can allow oil to leak through turbocharger seals. In normal engine operating condition, the pressure in the turbocharger end housings is higher than the bearing housing and oil/gas flows into the bearing housing, through the oil drain to the crankcase. Under certain operating conditions, such as low idle and thermal management, this pressure difference can be reversed with a higher bearing housing pressure than the pressure behind the turbine compressor wheel. Under this condition oil/gas will flow out of the bearing housing to the recess behind the compressor wheel. The bearing housing pressure will always track the
R, MAHESH BHARATHI
OIL AEROSOL EMISSION OPTIMISAITON IN HIGH POWER DIESEL ENGINE USING DEFLECTORS IN TURBO CHARGER OIL DRAIN CIRCUIT2024-26-00471/16/2024
Closed crankcase ventilation prevent harmful gases from entering atmosphere thereby reducing hydrocarbon emissions. Ventilation system carries blowby gases leaking through combustion process along with oil mist to Engine intake system. Major sources of blowby often occurs from leak in combustion chamber through piston rings, leaks from turbo shafts & valve guides. Oil mist carried away by blowby gases gets separated using filtration media. Fleece type separation media has high separation efficiency for particles above 10 microns. Efficiency drops if mist particle is below 10-micron size. Low size aerosol mist generally forms due to flash boiling on piston under crown area and on shafts of turbo charger due to high speeds combined with elevated oil temperatures. High power density diesel engine is taken for our study. It produces low particle size oil mist which contributes to aerosol emission of 3 gm/hr when operated at rated speed. Particle size measurement done using light refraction
M, Velshankar, Dharan R, Bharani, DHADSE, ASHISH, Permude, Ashok, Loganathan, Sekar
Cost Effective Pathways Toward Highly Efficient and Ultra-Clean Diesel Engines, Part II: Air-handling and Exhaust Aftertreatment2024-26-00441/16/2024
Following global trends of increasingly stringent greenhouse gas (GHG) and criteria pollutant regulations, India will likely introduce within the next decade equivalent Bharat Stage (BS) regulations for Diesel engines requiring simultaneous reduction in CO2 emissions and up to 90% reduction in NOx emission from current BS-VI levels. Consequently, automakers are likely to face tremendous challenges in meeting such emission reduction requirements while maintaining performance and vehicle total cost of ownership (TCO), especially in the Indian market which has experienced significant tightening of emission regulation during the past decade. Therefore, it is conceivable that cost effective approaches for improving existing diesel engines platforms for future regulations would be of high strategic importance for automakers. In this second of a two-part article, several component levels advancements are discussed including both engine and the aftertreatment system (ATS). For engine, role of
Kumar, Praveen, Shah, Ashish, Lago, Rafael, Echeverri Marquez, Manuel, Cleary, David, Gothekar, Sanjeev, Thipse, Sukrut S
Model based Charge control for 3-cylinder TGDI Miller engine containing variable geometry turbocharger2024-26-00431/16/2024
With the increase in the number of automobiles, there is a very strong emphasis on reducing the CO2 pollution which led to evolution of miller cycle engines. However, the inherent characteristic of Miller engine is the lower volumetric efficiency when compared to otto engines because of which small turbo chargers with variable geometry turbines are used to induct air into the engine. With miller engine and VGT turbo charger combination arises the challenges of charge controllability because of lower inertia and reduced vane control area. With conventional turbo charger control methods, the response time is slow thereby leading to turbo lag or sever over boosting, this is overcome by accurate engine modelling and using the same as input for charger control. In this study, model-based calibration approach was performed on a 1.2Litre 3 cylinder Miller GDI engine to model the charge exchange of the engine and use the same for determination required turbine vane positions to achieve the
Veeramani, Vivekanand, Karthi, Ramanathan, Shanmugam Ramakrishnan, Muthu
Optimization of HEV Vehicle’s Engine Modulated Noise2025-01-00845/5/2023
One 1.5L Miller-cycle turbocharged four cylinder gasoline hybrid engine is installed on a certain hybrid vehicle. When accelerating at low to medium speeds with a small throttle, there is a "da da" knocking noise inside the car, which seriously affects the overall sound quality of the vehicle. By analyzing the vibration and noise data of the engine, it was found that the frequency of the abnormal knocking sound is 200-1000Hz, which presents a half order characteristic in the time domain, that is, one knocking occurs when the engine crankshaft rotates twice. Through Hilbert demodulation analysis of the vibration data in the problem frequency range, it was found that the knocking noise was modulated in the frequency domain, with a modulation frequency of half of the crankshaft rotation frequency. By building a fully flexible multi-body dynamic model of a hybrid powertrain and inputting the engine's cylinder pressure excitation, the combustion excitation is coupled with mechanical
dan, Kong
Improvement of Transient Response on a Downsized 4 Cylinder Engine for Automobile Application2021-28-028010/1/2021
The automobile industry is one among the fastest in terms of adapting the technological advancements and evolving based on changing customer requirements. Researchers are focusing on making the automobiles better by means of making the vehicles more efficient, powerful and less polluting. In this study, venues of improving low end torque via improvement in volumetric efficiency as well as proper selection of turbochargers. An in-depth analysis of gas dynamics with respect to valve timing is studied along with the AVL boost simulation. It was found that volumetric efficiency starts to improve when there is a reduction in exhaust – exhaust valve overlap. There is an improvement found in the fresh air ratio (lambda) as the residual gas content is reduced. After the selection of valve timing, turbocharger optimization is done with comparison between two turbine sizes. Along with turbocharger comparison, technology comparison is also done namely between normal electronic VGT (Variable
Jain, Praveer Kirtimohan, Chendil, Chellapandi, Asthana, Shivam, Sanjay, Nehal, Meda, Venkata Saikumar, R, Sivasubramamanian, Daithankar, Parag, Ramadandi, Padmavathi, RS, Ranganathan, A, Guru Sankar
Time to boost analysis of an advanced boosting system for automotive applications2021-24-00939/5/2021
Fun to drive and drivability are important issues in modern vehicles, and propulsion system plays a key role in achieving these goals. Nowadays, most engines are characterized by the presence of a turbocharging system in order to obtain a high level of specific power and efficiency. Unfortunately, turbocharged engines are characterized by a delay in toque delivery, especially at low load, a phenomenon commonly called turbo-lag. In this paper an innovative turbocharging system is studied with the aim of providing a solution to this annoying behavior; a hybrid bosting system consisting of a traditional turbocharger and an electrically assisted compressor is analyzed. This architecture, especially thanks to the good dynamic behavior of the e-compressor, achieves the goal of an important reduction in terms of time-to-boost, providing an important improvement in engine readiness. The experimental campaign is carried out entirely on the test bench for components of the propulsion system of
Usai, Vittorio, Marelli, Silvia
An Optimized Design of Multi-Chamber Perforated Resonators to Attenuate Turbocharged Intake System Noise2021-01-06694/6/2021
The turbocharger air intake noise during transient conditions like wide open throttle and tip-in/out affects the passenger ride comfort. This paper aims to study an optimized design of multi-chamber perforated resonators to attenuate this noise. The noise produced by a turbocharger in a test vehicle has been measured to find out the noise spectral characteristics which can be used to design the acoustic targets including the amplitude and frequency range of transmission loss (TL). The structural parameters of the resonators are optimized based on genetic algorithm (GA) and two-dimensional prediction theory of the resonator TL. The optimized resonators are installed on the test vehicle to verify the actual noise reduction effect. The results suggest that the broadband noise has been eliminated, and subjective feelings are greatly improved.
Guo, Rong, Luo, Rui
Experimental and Numerical Investigation of a Turbocharger Turbine Using Exergy Analysis at Non-Adiabatic Conditions2020-01-22259/15/2020
Heat transfer in a turbocharger plays a crucial role in the optimization of turbocharger-engine matching process. Due to high temperature gradients between the hot exhaust gas compared to the compressor as well as the environment, it is well-known, that the heat loss from a turbocharger turbine is significant. Investigations of turbocharger performance are commonly done by quantifying the performance parameters under adiabatic conditions, following the paradigm of the first law of thermodynamics, based on the energy balance method. It turns out that an adiabatic assumption and the energy balance method is insufficient to provide a deep understanding about the aerothermodynamic effects on the turbine performance due to heat transfer. Based on the current state-of-the-art, this study aims to improve the characterization methods for passenger car turbocharger turbines, considering the impacts of heat transfer. Firstly, the turbocharger is measured on a hot gas test bench. Based on this
Lim, Shyang Maw, Kazemi Bakhshmand, Sina, Biet, Clemens, Mihaescu, Mihai
Investigation of H2 Formation Characterization and its Contribution to Post- Oxidation Phenomenon in a Turbocharged DISI Engine2020-01-21889/15/2020
In this research, simulation and experimental investigation of H2 emission formation and its influence during the post-oxidation phenomenon were conducted on a turbo-charged spark ignition engine. During the post-oxidation phenomenon phase, rich air-fuel ratio (A/F) is used inside the cylinder. This rich excursion gives rise to the production of H2 emission by various reactions inside the cylinder. It is expected that the generation of this H2 emission can play a key role in the actuation of the post-oxidation and its reaction rate if enough temperature and mixing strength are attained. It is predicted that when rich combustion inside the cylinder will take place, more carbon monoxide (CO)/ Total Hydro Carbon (THC)/ Hydrogen (H2) contents will arrive in the exhaust manifold. This H2 content facilitates in the production of OH radical which contributes to the post-oxidation reaction and in-turn can aid towards increasing the enthalpy. Through simulations, it was also investigated that
KUMAR, Madan, Moeeni, Salaar, Kuboyama, Tatsuya, Moriyoshi, Yasuo, Przewlocki, Jan, Tromellini, Rodolfo, Grill, Michael, Chiodi, Marco, Bargende, Michael
Parametric Study on Electric Turbocharging for Passenger Cars2020-01-22249/15/2020
The motor generator unit installed on the turbocharger shaft (MGU-H) provides a fundamental contribution to the amazing performances and efficiency of the last Formula 1 power units. The excess of exhaust gas energy - normally dumped through the waste-gate - can be converted into electric energy and used to push the car, by means of a second motor generator unit installed on the engine crankshaft (MGU-K). The goal of this paper is to assess pros and cons of the MGU-H technology when applied to a family of engines of different displacement, installed on a typical passenger car. The influence of engine size and cylinders layout is investigated, under the same set of hypotheses, considering both transient and steady engine operations. The baseline engine is a commercial 2.0 L, SI, 4-cylinder in-line, rated at 200 HP at 4500-5000 rpm. The study considers the following other SI configurations: a) 1.5L, 3-cylinder in-line, 150 HP; b) 3.0L, V6, 300 HP; c) 4.0L, V8, 400 HP; d) 6.0L, V12, 600
Mattarelli, Enrico, Scrignoli, Francesco, Rinaldini, Carlo Alberto
Driving Cycle Based Control and Calibration for a Turbocharged SI Engine with Low Pressure EGR System2020-01-20159/15/2020
Low pressure cooled EGR (LPEGR) for spark ignition (SI) engines is known to be one of the key technologies to benefit fuel consumption owing to lower pumping loss at part load, knock suppression capability and extended stoichiometric operating range thanks to combustion cooling effect. In order to implement this technology to industrialised application with the optimal performance efficiently and robustly, several challenges need to be solved, especially the EGR estimation accuracy and transport delay estimation accuracy during transient. And these challenges could be more complex on a turbocharged SI engine due to the much longer induction system, and more complex air path model due to the introduction of turbine, compressor and dump valve. This paper describes the control and calibration method for a turbocharged LPEGR engine, and the validation result in Worldwide harmonized Light vehicles Test Cycles (WLTC). The test result shows remarkable fuel benefit and accurate EGR estimation
Ma, He, Noguchi, Hidenori, Williams, Philip
Unsteady Simulation of Six-Inlet Pulsed-Flow Turbocharger Turbine2020-01-22379/15/2020
The turbochargers are driven by unsteady, pulsating flow. Such flow is generated by the exhaust phase of an internal combustion engine (ICE). A lot of turbocharger simulations are done during steady-state operation. Such simulations are favorable for turbocharger optimization at a certain operating point. However, the frequency and amplitude of exhaust pulses can heavily influence turbine performance. This paper presents the results of the three-dimensional (3-D) simulations of the six-inlet turbocharger turbine, under pulsating operation with a moving mesh approach. One of the key points of interest was the separation of the pressure pulses from the six-exhaust pipes during engine operation. The leakage between the exhaust pipes was analyzed at each time step at the different turbine speed. Another key point was the turbine response during pulsating flow at the different rotor speed. Parameter such as the turbine total-static efficiency under the single-pressure pulse was investigated
Kozak, Dariusz, Mazuro, Paweł
Analysis of the Boost System for a High Performance 2-Stroke Boosted Uniflow Scavenged Direct Injection Gasoline (BUSDIG) Engine2020-01-20079/15/2020
A 2-stroke boosted uniflow scavenged direct injection gasoline (BUSDIG) engine was researched and developed at Brunel University London to achieve higher power-to-mass ratio and thermal efficiency. In the BUSDIG engine concept, the intake scavenge ports are integrated to the cylinder liner and controlled by the movement of piston top while exhaust valves are placed in the cylinder head. Systematic studies on scavenging ports, intake plenum, piston design, valve opening profiles and fuel injection strategies have been performed to investigate and optimise the scavenging performance and in-cylinder fuel/air mixing process for optimised combustion process. In order to achieve superior power performance with higher thermal efficiency, the evaluation and optimisation of the boost system for a 1.0 L 2-cylinder 2-stroke BUSDIG engine were performed in this study using one dimensional (1D) engine simulations. The results show that the engine exhaust valve opening (EVO) timing and exhaust
Wang, Xinyan, Zhao, Hua
Lean-Burn Stratified Alcohol Fuels Engines of Power Density up to 475 kW/Liter Featuring Super-Turbocharging, Rotary Valves, Direct Injection, and Jet Ignition2020-01-20369/15/2020
Direct injection (DI) and jet ignition (JI), plus assisted turbocharging, have been demonstrated to deliver high efficiency, high power density positive ignition (PI) internal combustion engines (ICEs) with gasoline. Peak efficiency above 50% and power density of 340 kW/liter at the 15,000 rpm revolution limiter working overall λ=1.45 have been report-ed. Here we explore the further improvement in power density that may be obtained by replacing gasoline with ethanol or methanol, thanks to the higher octane number and the larger latent heat of vaporization, which translates in an increased resistance to knock, and permits to have larger compression ratios. Results of simulations are proposed for a numerical engine that uses rotary valves rather than poppet valves, while also using mechanical, rather than electric, assisted turbocharging. While with gasoline, the power density is 410-420 kW/liter, the use of oxygenates permits to achieve up to 475 kW/liter working with methanol.
Boretti, Alberto
The Potential of Exhaust Waste Heat Use in a Turbocharged Diesel Engine for Charge Air Cooling2020-01-20899/15/2020
Even a basic analysis of the use of fuel energy in a combustion engine would indicate that one-third of fuel energy is converted into exhaust waste, which is released into the environment. The scale of energy loss encourages scientists to try to consider the waste heat of exhaust gases as a potential source of useful energy. It is a standard today that waste heat is commonly used to power a turbocharger applied to internal combustion engines. Waste heat can also be used to drive an adsorption cooling system for air-conditioning inside the car. The drawback of that solution is complexity of the system and size of adsorption bed which make it not suitable for automotive industry use. The concept of increasing the capability of vehicles’ turbo engines can boost performance of turbo-charged engines through extra cooling of air being impelled into the combustion chamber of the engine. Cooling of the charge inside the intake manifold saves fuel and reduces nitric oxide emissions in exhaust
Danilecki, Krzysztof, Eliasz, Jacek
Mercedes-AMG ready with electrically-assisted turbocharger20AUTP08_087/1/2020
In announcement signaling automakers continue significant R&D for internal-combustion propulsion, Mercedes-AMG said it is preparing to launch a new, electrically-assisted turbocharger for engines to power its next vehicle generation. Confirming that the new turbocharger design will soon be fitted in a “series production” model line, the company said the electrically augmented turbocharger delivers enhanced driving dynamics while also improving efficiency. Mercedes-Benz and other automakers already have launched auxiliary electric compressors to augment conventional turbochargers, but this design integrates the strategy by using the electric machine to act directly on shaft connecting the turbine and compressor wheels: the 1.6-inch (41-mm)-wide motor sits between the exhaust-driven turbine and the impeller that compresses the intake air directed into the engine. It can spin to a conventional turbocharger rate of up to 170,000 rpm.
Visnic, Bill
Experimental Evaluation of Steady State Performance of an Automotive Electric Supercharger2020-37-00086/23/2020
Nowadays, the electric supercharger for turbocharged downsized automotive engines is mainly used to improve torque at low engine speeds in order to obtain an improvement of the time to boost. These components are usually designed to fill the gap in terms of torque in transient operation caused by the main turbocharger with reference to the typical turbo lag issues. An advanced solution of the engine boosting system was taken into account, considering the adoption of an e-booster system coupled to a waste-gated turbocharger, typically adopted alone in order to provide a reduced turbo-lag, i.e. an optimized transient response of the system. In the experimental activity described in this work, the maximum speed of the e-booster used is about 70000 rpm, the maximum pressure ratio is 1.5 and the maximum power required on the shaft is less than 4 kW. The compressor unit have to be maintained in the idle condition in order to avoid excessive electric consumption and overheating problem when
Marelli, Silvia, Usai, Vittorio
WHAT WE'RE DRIVING20AUTP04_084/1/2020
For the Lincoln of my experience - and I'm not particularly young - I haven't been able to understand the “sell” of the brand. Low sales numbers and decades of declining prestige seemed to have long indicated a “cut your losses” argument for Ford to ditch its premium marque. But if the 2020 Aviator is the building block of things to come, there's hope. This all-new platform, sensibly shared with the volume-play Ford Explorer, returns Lincoln to the longitudinal engine/rear-drive layout that luxury vehicles are supposed to have. As a result, the Aviator is as responsive and athletic as you can expect a three-row, 16.5-foot-long crossover to be.
Surge Prediction in a Single Sequential Turbocharger (SST) Compressor Using Computational Fluid Dynamics2019-01-14906/5/2019
The Single Sequential Turbocharger (SST) used in Ford’s 6.7L Scorpion Diesel is analyzed using Computational Fluid Dynamics (CFD) to draw conclusions about the compressor stability at low mass flows. The SST compressor concept consists of a double-sided wheel which flows in parallel fed by two separate inlets (front and rear), followed by a single vane-less diffuser, and a volute. CFD simulations for the full stage are performed at low mass flow rates Both, front and rear, sides have ported shroud casing-treatment (CT) in the inlet region. An objective of the analysis is to determine which side of the SST unit compressor (front or rear on the double-sided wheel) suffers flow break down first as the mass flow is reduced, and its impact on the overall stability of the SST compressor. Another objective is to better understand the interactions between the compressor inlet flow and the flow through the casing-treatment. It has been observed that these interactions reduce the effectiveness
Karim, Ahsanul, Wade, Robert, Morelli, Anthony, Miazgowicz, Keith, Lizotte, Brian
New Psychoacoustic Criteria for Turbocharger Aero Noise2019-01-14896/5/2019
With ever more stringent regulations related to air pollution and CO2 emissions, there is a growing trend to address this through the downsizing of automotive engines. Turbochargers are used to improve engine power by using exhaust gas energy to provide boosted air pressure for better efficiency. They are a key element in powertrains of today and in the future. During real operating conditions, the rotational speed of a turbo varies greatly making this rotating machinery run in “continuous transient” phases and produces unwanted noises as a result. Recently, we identified a new source of aero noise while developing a new type of turbocharger. Our typical in-house procedure for characterizing usual aero broad band noise source was to use the 3-microphone methodology for measuring the acoustic intensity. However, this methodology is not well adapted if the noise source is tonal, not constant over time and includes high frequency content, which is the case with the new type of
Rigault, Alexandre, Kihm, Fred, Baron, Nicolas
Prediction of Broadband Noise in an Automotive Centrifugal Compressor with Three-Dimensional Computational Fluid Dynamics Detached Eddy Simulations2019-01-14876/5/2019
Centrifugal compressors for automotive turbochargers must operate over wide speed and flow ranges to provide the required air pressure and mass flow rate to the intake manifold of the internal combustion engines. At a fixed rotational speed, the flow field near the inducer of the impeller becomes increasingly unstable with decreasing flow rate, as the incidence angle grows between the air flow approaching the impeller, relative to the tangent of the main impeller blades at the leading edge. Flow field measurements conducted earlier have revealed that once the incidence angle exceeds a critical value (nearly independent of rotational speed) of approximately 15°, reversed flow near the periphery (blade tips) starts penetrating upstream of the impeller, with a high tangential velocity in the direction of impeller rotation. As the incidence angle is increased towards this critical value, whoosh noise elevates, where it remains high for a significant portion of the mid-flow operating range
Dehner, Rick, Selamet, Ahmet
On the Measurement and Simulation of Flow-Acoustic Sound Propagation in Turbochargers2019-01-14886/5/2019
Most of today’s internal combustion engines are turbocharged by combined radial compressors and turbines for downsizing. This mostly leads to reduced orifice noise of both intake and exhaust systems, but the detailed damping mechanisms remain yet unknown. Intake and exhaust systems are developed with 1D-CFD simulations, but validated acoustic sub-models for turbochargers are not yet available. Therefore the aim of this publication is studying the turbocharger’s silencing capabilities and subsequently develop new acoustic turbocharger models. The acoustic properties of the turbocharger can be well described by transmission loss. In addition to thermodynamic variations, parameter variations with wastegate and VTG systems were also performed. A total of four turbochargers of very different sizes were investigated. Low frequency attenuation is dominated by impedance discontinuities, increasing considerably with mass flow and pressure ratio. High frequency transmission loss is generated by
Ruppert, Hendrik, Falke, Felix, Pischinger, Stefan, Günther, Marco, Stienen, Ralf
Agglomeration and Nucleation of Non-Volatile Particles in a Particle Grouping Exhaust Pipe of a Euro VI Heavy-Duty Diesel Engine2019-01-00441/15/2019
The possibility of non-volatile particle agglomeration in engine exhaust was experimentally examined in a Euro VI heavy duty engine using a variable cross section agglomeration pipe, insulated and double walled for minimal thermophoresis. The agglomeration pipe was located between the turbocharger and the exhaust treatment devices. Sampling was made across the pipe and along the centre-line of the agglomeration pipe. The performance of the agglomeration pipe was compared with an equivalent insulated straight pipe. The non-volatile total particle number and size distribution were investigated. Particle number measurements were conducted according to the guidelines from the Particle Measurement Programme. The Engine was fuelled with commercially available low sulphur S10 diesel. Experiments conducted in heavy duty engine relevant operating points were done to sweep the effect of (i) Mass flow rate in the exhaust (ii) Temperature in the exhaust and (iii) Engine speed and thus exhaust
K, Arun Prasath, Stenlaas, Ola, Bernemyr, Hanna, Erlandsson, Anders
2-Stroke Engine Options for Automotive Use: A Fundamental Comparison of Different Potential Scavenging Arrangements for Medium-Duty Truck Applications2019-01-00711/15/2019
The work presented here seeks to compare different means of providing scavenging systems for an automotive 2-stroke engine. It follows on from previous work solely investigating uniflow scavenging systems, and aims to provide context for the results discovered there as well as to assess the benefits of a new scavenging system: the reverse-uniflow sleeve-valve. For the study the general performance of the engine was taken to be suitable to power a medium-duty truck, and all of the concepts discussed here were compared in terms of indicated fuel consumption for the same cylinder swept volume using a one-dimensional engine simulation package. In order to investigate the sleeve-valve designs layout drawings and analysis of the Rolls-Royce Crecy-type sleeve had to be undertaken. A new methodology for optimization was developed and the analysis process also took into account work done by the charging system, this being assumed to be a combination of supercharger and turbocharger to permit
Turner, James W. G., Head, Robert A., Chang, Junseok, Engineer, Nayan, Wijetunge, Roshan, Blundell, David W., Burke, Paul
FSI - MRF Coupling Approach For Faster Turbocharger 3D Simulation2019-01-00071/15/2019
Fluid-Structure Interaction (FSI) simulation approach can be used to simulate a turbocharger. However, this predictive 3D simulation encounters the challenge of a long computational time. The impeller speed can be above 100,000 rpm, and generally a CFD solver limits the maximum movement of the impeller surface per time step. The maximum movement must be a fraction (~0.3) of the cell length, thus the time step will be very small. A Multiple Reference Frame (MRF) approach can reduce computational time by eliminating the need to regenerate the mesh at each time-step to accommodate the moving geometry. A static local reference zone encompassing the impeller is created and the impact of the impeller movement is modeled via a momentum source. However, the MRF approach is not a predictive simulation because the impeller speed must be given by the User. A new simulation approach was introduced that coupled the FSI and MRF approach. Like in the FSI approach, the total moment of the impeller was
Abidin, Zainal, Morris, Andrew, Miwa, Jason, Sadique, Jasim, Wang, Yunliang
WHAT WE'RE DRIVING19AUTP08_121/1/2019
Toyota sought to channel its 2000 GT and Supra sportscar heritage with the introduction of the 2020 Supra, but in the process the company also forecast the future. Acknowledging the SUV-centric product-development investment reality of 2019, Toyota partnered with BMW, which was in position to supply a six-cylinder engine with the Supra's traditional inline configuration, while contracting assembly to Austria's Magna Styr.
Porsche reveals eighth-generation of fabled 91119AUTP01_151/1/2019
Regularly updating and evolving the Porsche 911's aesthetic signature might seem an impossible task. But more than half a century after its birth, the unveiling of the eighth-generation at the 2018 L.A. Auto Show demonstrated that it is in fact still a totally possible art-with design boss Michael Mauer the chief artist. Designated in-house as the 992 series and slightly larger than the outgoing 991, it is launched in rear-wheel-drive and all-wheel-drive forms-Carrera S and Carrera 4S-and now only in the wide-body width previously used for the Carrera 4 GT3 and GTS, instead of two body widths. Across the nose, the new 911 is 45 mm (1.8 in) wider than the outgoing version, a figure some 911 purists may look at askance, as growth in recent years has already been considerable.
Birch, Stuart
Cadillac pulls the wraps off two new V-Series sedans19AUTP08_191/1/2019
Cadillac has added two more sedans to its V-Series performance lineup, the 2020 CT4-V and CT5-V. The CT4-V will square off against established C-segment players such as the BMW 3-Series and Mercedes-Benz C-Class, along with Hyundai's new Genesis G70. The CT5-V will compete with the BMW 5-Series and Audi A6. The two new 4-door sedans join the larger 2019 CT6-V sedan in the V-Series stable, though the company noted that the series is evolving to be less focused on hard-core, track-worthy machines, and more about sporty and comfortable daily drivers. “We are inviting even more customers into the V-Series family,” said Brandon Vivian, Cadillac executive chief engineer, “by adding a new level of elevated performance between our Sport models and the ultimate, high-performance track capability that the V-Series has grown to represent.”
Seredynski, Paul
WHAT WE'RE DRIVING18AUTP10_0510/1/2018
Mercedes-Benz is fond of saying it cascades at least some of the S-Class' posh luxury and technology throughout its range. That's just what it has done for the fourth-generation A-Class, the nameplate that sits at the bottom of the brand's lineup. The new A-Class is heaped with cabin tech, in particular. Built on Mercedes' MFA2 front-wheel-drive platform, the A200 AMG Line version driven is well-connected, having the MBUX (Mercedes-Benz User Experience) touchscreen interface (and a touchpad), plus “Hey Mercedes” voice recognition.
Effective Suppression of Surge Instabilities in Turbocharger Compression Systems through a Close-Coupled Compressor Inlet Restriction2018-01-17149/10/2018
The current work demonstrates effective suppression of compression system surge instabilities by installing a variable cross-sectional flow area restriction within the inlet duct of a turbocharger centrifugal compressor operating on a bench-top facility. This restriction couples with the compressor, similar to stages in a multi-stage turbomachine, where the effective pressure ratio is the product of those for the restriction and compressor. During experiments at constant compressor rotational speed, the compressor is stable over the negatively sloped portion of the pressure ratio vs. flow rate characteristics, so the restriction is eliminated within this operating region to preserve compressor performance. At low flow rates, the slope of the compressor alone characteristics reaches a positive value, and the unrestricted compression system enters mild surge. Further reduction of flow rate with the unrestricted compressor inlet results in a sudden transition to deep surge instabilities
Dehner, Rick, Selamet, Ahmet, Miazgowicz, Keith
Development of a New 1.8L Down-Speeding Turbocharged Gasoline Engine with Miller Cycle2018-01-17129/10/2018
Upcoming China 4th stage of fuel consumption regulation and China 6a emission legislation require improvement of many existing engines. This paper summarizes an upgrade of combustion system and mechanical layout for a four-cylinder engine family. Based on an existing production process for a naturally aspirated 2.0-liter gasoline engine, a 1.8-liter down-speeded and turbocharged gasoline engine is derived. Starting development by analysis of engine base geometry, a layout for a Miller-Cycle gas exchange with early closing of intake valves is chosen. Requirements on turbocharger configuration are investigated with one-dimensional gas exchange simulation and combustion process will be analyzed by means of 3D-CFD simulation. Challenging boundary conditions of a very moderate long-stroke layout with a stroke/bore-ratio of only 1.037 in combination with a cost efficient port fuel injection system and fixed valve lift profiles are considered. To compensate reduced in-cylinder charge motion
Ye, Yisu, Xu, Libing, Wang, Jinshi, Yao, Kefu, Zhao, Mingxiang, Dieterich, Carsten, Souren, Mike, Morcinkowski, Bastian
Effect of Mesh Size in Numerical Simulation of Turbine Housing in Turbocharger2018-01-17159/10/2018
Numerical method is popular in analyzing turbine housing in turbocharger with an early and rapid risk assessment. However, complex casting and extreme thermal loading from exhaust gas temperature and flow variation under engine duty cycle lead to big thermal stress and this makes material serviced in the plastic zone. Previous numerical simulations show that a mesh size is insensitive to the elastic finite element analysis (FEA), but might not be proper for elastic-plastic FEA, even that other boundary conditions keep same, which indicating simulation results are changeable with mesh size and a simple numerical mesh size convergence might not be enough to guarantee accurate numerical results as well. Therefore, several different mesh sizes are used in elastic-plastic analysis of turbine housing to investigate the influence on numerical results. Based on the numerical results and their comparison, we conclude that theoretical results exist under smaller finite element size but it is
Guo, Henry, Long, Haiyang
Experimental Investigation on Surge Phenomena in an Automotive Turbocharger Compressor2018-01-09764/3/2018
Downsizing and turbocharging are today considered an effective way to reduce CO2 emissions in automotive gasoline engines, especially for the European and US markets. In the broad field of research and development for engine boosting systems, the instability phenomenon of surge has gathered considerable interest in recent years, as the main limiting factor to high performance boosting and boost pressure control. To this extent, developing an in-depth knowledge of the surge dynamics and on the phenomena governing the transition from stable to unstable operation can provide very valuable information for the design of the intake system and boost pressure control algorithms, allowing optimal boost pressure without compromising the transient response. This paper describes an experimental study that aims at better understanding the phenomena leading to the inception of surge, and exploring the effects of the downstream circuit geometry on the compressor dynamic behavior in surge and prior to
Marelli, Silvia, Misley, Anna, Silviestri, Paolo, Capobianco, Massimo, Taylor, Alexandra, Canova, Marcello
Use of Water-Butanol Blends in a Turbocharged Common Rail Dual Fuel Engine for Enhanced Performance and Reduce Smoke Levels2018-01-02514/3/2018
Experiments were conducted on a turbocharged three cylinder automotive common rail diesel engine with port injection of butanol. This dual fuel engine was run with neat butanol and blends of water and butanol (up to 20% water by mass). Experiments were performed at a constant speed of 1800 rpm and a brake mean effective pressure of 11.8 bar (full load) at varying butanol to diesel energy share values while diesel was either injected as a single pulse or as twin pulses (Main plus Post). Open engine controllers were used for varying the injection parameters of diesel and butanol. Water butanol blends improved the brake thermal efficiency by a small extent because of better combustion phasing as compared to butanol without water. When the butanol to diesel energy share was high, auto-ignition of butanol occurred before the injection of diesel. This lowered the ignition delay of diesel and hence elevated the smoke level. Two separated heat release phases along with high rates of pressure
Yadav, Jaykumar, Ramesh, A
Numerical and Experimental Investigation of Effect of Tongue Shape on Turbine Reliability2018-01-04834/3/2018
Turbine housing in turbocharger is a critical part which must withstand severe cyclic mechanical and thermal load throughout its service life. The combination of thermal transients with mechanical load cycles results in a complex evolution of damage, leading to thermal mechanical fatigue (TMF) of the material and, after a certain number of loading cycles, to failure of the component. The volute tongue at radial turbine housing is a key feature which is frequently the first location subject to thermal crack failure due to turbine design. Design of tongue is of importance to improve system's TMF performance. In this work, two tongues including square and elliptic shape on radial turbine fatigue are studied. TMF performance is evaluated by finite element analysis (FEA). In particular, experimental method is carried out in order to validate the simulation model. The good agreement is found between numerical and experimental results. Based on both numerical and experimental investigation we
Guo, Henry, Jia, Wenchuan, Li, Na
Evaluation of Engine-Related Restrictions for the Global Efficiency by Using a Rankine Cycle-Based Waste Heat Recovery System on Heavy Duty Truck by Means of 1D-Simulation2018-01-14514/3/2018
As a promising concept to improve fuel efficiency of a long-haul heavy duty truck with diesel engine, organic Rankine cycle (ORC) based waste heat recovery system (WHR) by utilizing the exhaust gas from internal combustion engine has continuously drawn attention from industry in recent years. The greatest achievable global efficiency may be, however, restricted by the engine. On one hand, engine operating conditions have direct impact on the temperature and the mass flow of exhaust gas, which is the waste heat source, on the other hand, the engine cooling system limits the heat rejection from the condenser of the WHR system. This paper aims to evaluate the impacts of the varied engine applications considering the effects of the WHR system on the global efficiency and engine emissions. A complex 0D/1D-simulation model for a turbocharged production heavy duty engine with low-/high-temperature cooling circuit and a WHR system with ethanol as working fluid have been established in GT-Suite
Yang, Kangyi, Bargende, Michael, Grill, Michael
Development of a New 2L Gasoline VC-Turbo Engine with the World’s First Variable Compression Ratio Technology2018-01-03714/3/2018
A new 2L gasoline turbo engine, named KR20DDET was developed with the world’s first mass-producible variable compression turbo (VC-Turbo) technology using a multi-link variable compression ratio (VCR) mechanism. It is well known that increasing the compression ratio improves gasoline engine thermal efficiency. However, there has always been a compromise for engine designers because of the trade-off between increasing the compression ratio and knocking. At Nissan we have been working on VCR technology for more than 20 years and have now successfully applied this technology to a mass production engine. This technology uses a multi-link mechanism to change the top and bottom dead center positions, thereby allowing the compression ratio to be continuously changed. The VC-Turbo engine with this technology can vary the compression ratio from 14:1 for obtaining high thermal efficiency to 8:1 for delivering high torque by taking advantage of the strong synergy with turbocharging. This enables
Kojima, Shuji, Kiga, Shinichi, Moteki, Katsuya, Takahashi, Eiji, Matsuoka, Kazuya
Turbocharger Impact on Diesel Electric Powertrain Performance2018-01-09654/3/2018
When electrifying the powertrain, there arises an opportunity to revise the traditional turbocharging trade-off between fuel-economy and transient performance. With the help of electrification, it might be possible to make the trade-off in favor of fuel economy, since transient response can be improved by the electric machine. The paper investigates this trade-off by looking at three turbocharger selections. A conventionally dimensioned turbocharger, an efficiency optimized turbocharger with maintained flow capacity, and an efficiency optimized turbocharger with increased flow capacity. The concepts are evaluated on the following cases: stationary operation, engine tip-in performance, vehicle acceleration performance, and on road fuel economy performance. The investigation is based on a validated mean value engine model of a six cylinder inline CI engine, and on a validated driveline and vehicle model of a heavy-duty truck. The evaluations are made with the help of simulations and
Leek, Alf Erik Viktor, Eriksson, Lars
Diesel Engine Cylinder Deactivation for Improved System Performance over Transient Real-World Drive Cycles2018-01-08804/3/2018
Effective control of exhaust emissions from modern diesel engines requires the use of aftertreatment systems. Elevated aftertreatment component temperatures are required for engine-out emissions reductions to acceptable tailpipe limits. Maintaining elevated aftertreatment components temperatures is particularly problematic during prolonged low speed, low load operation of the engine (i.e. idle, creep, stop and go traffic), on account of low engine-outlet temperatures during these operating conditions. Conventional techniques to achieve elevated aftertreatment component temperatures include delayed fuel injections and over-squeezing the turbocharger, both of which result in a significant fuel consumption penalty. Cylinder deactivation (CDA) has been studied as a candidate strategy to maintain favorable aftertreatment temperatures, in a fuel efficient manner, via reduced airflow through the engine. This work focuses on prediction and demonstration of fuel economy benefits of CDA when
Joshi, Mrunal, Gosala, Dheeraj, Allen, Cody, Srinivasan, Sirish, Ramesh, Aswin, VanVoorhis, Matthew, Taylor, Alexander, Vos, Kalen, Shaver, Gregory, McCarthy Jr, James, Farrell, Lisa, Koeberlein, Edward D.
Testing and Implementation of a Turbocharged Formula SAE Vehicle2018-01-09674/3/2018
Research on turbocharging for FSAE at the University of Malta, has been ongoing for a number of years. 1D simulations were done to determine best design configuration and determine a lowered compression ratio. A decompression plate was installed on the Kawasaki 600 cc engine. Calibration of the engine was performed on the engine dynamometer. A hot-gas test stand for testing of the turbocharger was developed. The turbocharger speed was measured by a custom built hall-effect sensing setup that is compact enough to be implemented also in the FSAE vehicle. Bespoke camshafts with optimized valve timing determined through WAVE 1D simulations and designed with Valdyn® were machined. The turbocharged setup was used on the University of Malta FSAE vehicle in the FSAE Italy 2017 competition. Knock was investigated through in-cylinder pressure measurements and use of commercial knock sensor on the 600 cc engine. Benchmarking in-cylinder pressure measurement tests were carried out on a 1.4 liter
Azzopardi, Jean Paul, Farrugia, Jean-Paul, Caruana, Carl, Grech, Nicholas, Farrugia, Nicholas, Chircop, Marlon, Farrugia, Mario, Farrugia, Michael
Steady-State Experimental and Meanline Study of an Asymmetric Twin-Scroll Turbine at Full and Unequal and Partial Admission Conditions2018-01-09714/3/2018
The use of twin-scroll turbocharger turbines has gained popularity in recent years. The main reason is its capability of isolating and preserving pulsating exhaust flow from engine cylinders of adjacent firing order, hence enabling more efficient pulse turbocharging. Asymmetrical twin-scroll turbines have been used to realize high pressure exhaust gas recirculation (EGR) using only one scroll while designing the other scroll for optimal scavenging. This research is based on a production asymmetrical turbocharger turbine designed for a heavy duty truck engine of Daimler AG. Even though there are number of studies on symmetrical twin entry scroll performance, a comprehensive modeling tool for asymmetrical twin-scroll turbines is yet to be found. This is particularly true for a meanline model, which is often used during the turbine preliminary design stage. This study presents the development of a generalized meanline model for a twin-scroll turbine, which can be used in the early design
Palenschat, Torsten, Mueller, Markus, Rajoo, Srithar, Chiong, Meng Soon, Newton, Peter, Martinez-Botas, Ricardo, Tan, Feng Xian
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