Observations on and potential trends for mechanically supercharging a downsized passenger car engine:a review

Engine downsizing is a proven approach for achieving a superior fuel efficiency. It is conventionally achieved by reducing the swept volume of the engine and by employing some means of increasing the specific output to achieve the desired installed engine power, usually in the form of an exhaust-driven turbocharger. However, because of the perceptible time needed for the turbocharger system to generate the required boost pressure, a characteristic of turbocharged engines is their degraded driveability in comparison with those of their naturally aspirated counterparts. Mechanical supercharging refers to the technology that compresses the intake air using the energy taken directly from the engine crankshaft. It is anticipated that engine downsizing which is realised either solely by a supercharger or by a combination of a supercharger and a turbocharger will enhance a vehicle’s driveability without significantly compromising the fuel consumption at an engine level compared with the downsizing by turbocharging. The capability of the supercharger system to eliminate the high exhaust back pressure, to reduce the pulsation interference and to mitigate the surge issue of a turbocharged engine in a compound-charging system offsets some of the fuel consumption penalty incurred in driving the supercharger. This, combined with an optimised down-speeding strategy, can further improve the fuel efficiency performance of a downsized engine while still enhancing its driveability and performance at a vehicle level. This paper first reviews the fundamentals and the types of supercharger that are currently used, or have been used, in passenger car engines. Next, the relationships between the downsizing, the driveability and the down-speeding are introduced to identify the improved synergies between the engine and the boosting machine. Then, mass production and prototype downsized supercharged passenger car engines are briefly described, followed by a detailed review of the current state-of-the-art supercharging technologies that are in production as opposed to the approaches that are currently only being investigated at a research level. Finally, the trends for mechanically supercharging a passenger car engine are discussed, with the aim of identifying potential development directions for the future. Enhancement of the low-end torque, improvement in the transient driveability and reduction in low-load parasitic losses are the three main development directions for a supercharger system, among which the adoption of a continuously variable transmission to decouple the supercharger speed from the engine speed, improvement of the compressor isentropic and volumetric efficiency and innovation of the supercharger mechanism seem to be the potential trend for mechanically supercharging a passenger car engine.

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Multidisciplinary Simulation Model for the Balancing of Powertrain Combustion, Control and Components for Optimal Fuel Consumption, Emissions, Cost and Performance for a Diesel Engine Powered Passenger Car

10.4271/2012-01-1572 ◽

2012 ◽

Author(s):

Fredrik B. Ekstrom ◽

Joop Somhorst

Keyword(s):

Diesel Engine ◽

Simulation Model ◽

Fuel Consumption ◽

Combustion Control ◽

Passenger Car ◽

And Performance ◽

Multidisciplinary Simulation ◽

Optimal Fuel Consumption

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Passenger-Car Fuel Consumption Versus Performance in Retrospect

Volume 2: Large-Bore Engines, Fuel Effects, Homogeneous Charge Compression Ignition, Engine Performance and Simulation ◽

10.1115/2001-ice-411 ◽

2001 ◽

Author(s):

Charles A. Amann

Keyword(s):

Fuel Consumption ◽

Fuel Economy ◽

Environmental Protection Agency ◽

Protection Agency ◽

Passenger Car ◽

Acceleration Time ◽

Performance Metric ◽

And Performance ◽

Standing Start ◽

Engine Power

Abstract Over the last quarter of the 1900s, the U.S. Environmental Protection Agency (EPA) has annually tabulated the fuel economy and performance characteristics of the new passenger-car fleet. Fuel economy was measured over the EPA combined urban and highway driving schedules. The performance metric was the estimated acceleration time from a standing start to 60 miles per hour (mph). In the present study, the interplay among factors influencing these characteristics is reviewed. Then, for the average new car in a given year, the manner in which fuel consumption and acceleration time are influenced by vehicle weight and engine power are examined. The departure of individual vehicles from this average trend is considered. Finally, a few of the prominent powertrain characteristics responsible for improvements in the tradeoff between fuel consumption and performance are listed.

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Forecasting of a boosted locomotive gas diesel engine parameters with one- and two-stage charging systems

Reports in Mechanical Engineering ◽

10.31181/rme200101192s ◽

2020 ◽

Vol 1 (1) ◽

pp. 192-198

Author(s):

Vladimir V. Sinyavski ◽

◽

Mikhail G. Shatrov ◽

Vladislav V. Kremnev ◽

Pronchenko Grigori ◽

...

Keyword(s):

Diesel Engine ◽

Fuel Injection ◽

Fuel Efficiency ◽

Air Pressure ◽

Zone Model ◽

Boost Pressure ◽

Two Stage ◽

Charging System ◽

Locomotive Engine ◽

The Right

Conversion of locomotive engines for operation on natural gas lowers considerably expenses for fuel and reduces exhaust emissions which makes it possible to omit large and expensive aftertreatment systems. The permanent need to raise the engine power requires a considerable increase of the boost pressure. This can be realized by using a high pressure turbocharger or a two-stage charging system. In the research, parameters of a high boosted D200 6-cylinder locomotive engine having D/S=200/280 mm are forecasted using a one-zone model developed in MADI. An analysis was carried out to explain why the 1st stage compressor of the two-stage charging system should be specially profiled to have its map tilted to the right. Calculations were performed for the gas diesel engine having a break mean effective pressure (BMEP) 2.7 MPa with one and two-stage charging systems. In both cases, close fuel efficiency was obtained, though for the two-stage charging system, the boost air pressure was higher. The engine with one turbocharger had no reserves for further power augmentation while the two-stage charging system enabled to increase the boost air pressure further. Therefore, parameters of the engine having a higher BMEP 3.2 MPa were calculated. In that case, not to exceed the peak combustion pressure, a retarded fuel injection was used which resulted in fuel efficiency drop by approximately 1.5%.

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Efficiency of using inverter power plants as part of multifunctional energy technology complexes

RUDN Journal of Engineering Researches ◽

10.22363/2312-8143-2020-21-4-244-253 ◽

2020 ◽

Vol 21 (4) ◽

pp. 244-253

Author(s):

Ivan Ya. Redko ◽

Andrey A. Malozemov ◽

Georgiy A. Malozemov ◽

Alexey V. Naumov ◽

Dmitry V. Kozminykh

Keyword(s):

Power Plant ◽

Fuel Consumption ◽

Damage Accumulation ◽

Power Plants ◽

Fuel Efficiency ◽

Point Of View ◽

Operating Conditions ◽

Simultaneous Increase ◽

Boost Pressure ◽

Engine Operation

A method has been developed for a comprehensive multi-criteria assessment of the efficiency of using inverter power plants as part of multifunctional energy-technological complexes with technical solutions aimed at reducing the negative consequences of the internal combustion engine operation with an optimal from the point of view of fuel efficiency speed. The method includes: synthesis of the optimal engine speed control algorithm, determination of the complex operating modes under operating conditions, assessment of changes in fuel consumption and harmful substances emissions with exhaust gases and resource consumption rate when the engine is switched to the operating mode with the optimal speed, complex technical and economic assessment of the inverter power plants efficiency. On the example of an inverter power plant with a capacity of 100 kW, the need to apply the method is proved. It was found that the engine operation with the optimal from the point of view of fuel efficiency speed and without additional design measures entails an increase in the damage accumulation rate by 1.7-2.1 times and therefore is economically inexpedient, despite a decrease in fuel consumption by 1% or more. It was found that a decrease in the compression ratio with a simultaneous increase in the boost pressure makes it possible to increase the engine resource up to a functional failure due to damage accumulation by 43% and to a parametric failure due to wear by 32%, while the operating costs of the inverter power plant will decrease by 3.7% relative to the base (no changes) power plants. The emission of soot particles will decrease by about 2 times, nitrogen oxides - by 2%, hydrocarbons - almost to zero.

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Application of Box-Behnken Analysis on the Optimisation of Air Intake System for a Naturally Aspirated Engine

International Journal of Automotive and Mechanical Engineering ◽

10.15282/ijame.17.2.2020.21.0602 ◽

2020 ◽

Vol 17 (2) ◽

pp. 8029-8042

Author(s):

N.S. Mustafa ◽

N.H.A. Ngadiman ◽

M.A. Abas ◽

M.Y. Noordin

Keyword(s):

Fuel Consumption ◽

Fuel Efficiency ◽

Engine Performance ◽

Fuel Price ◽

Design Expert ◽

Intake System ◽

Analysis Technique ◽

System Components ◽

Air Intake ◽

High Influence

Fuel price crisis has caused people to demand a car that is having a low fuel consumption without compromising the engine performance. Designing a naturally aspirated engine which can enhance engine performance and fuel efficiency requires optimisation processes on air intake system components. Hence, this study intends to carry out the optimisation process on the air intake system and airbox geometry. The parameters that have high influence on the design of an airbox geometry was determined by using AVL Boost software which simulated the automobile engine. The optimisation of the parameters was done by using Design Expert which adopted the Box-Behnken analysis technique. The result that was obtained from the study are optimised diameter of inlet/snorkel, volume of airbox, diameter of throttle body and length of intake runner are 81.07 mm, 1.04 L, 44.63 mm and 425 mm, respectively. By using these parameters values, the maximum engine performance and minimum fuel consumption are 93.3732 Nm and 21.3695×10-4 kg/s, respectively. This study has fully accomplished its aim to determine the significant parameters that influenced the performance of airbox and optimised the parameters so that a high engine performance and fuel efficiency can be produced. The success of this study can contribute to a better design of an airbox.

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Effect of Methanol/Water Mixed Fuel Compound Injection on Engine Combustion and Emissions

Energies ◽

10.3390/en14154491 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4491

Author(s):

Changchun Xu ◽

Haengmuk Cho

Keyword(s):

Fuel Consumption ◽

Ignition Delay ◽

Fuel Injection ◽

Fuel Efficiency ◽

Engine Performance ◽

Hydroxyl Group ◽

Combustion Mechanism ◽

Performance And Emission ◽

Reduce Emissions ◽

Concentration Ratios

Due to the recent global increase in fuel prices, to reduce emissions from ground transportation and improve urban air quality, it is necessary to improve fuel efficiency and reduce emissions. Water, methanol, and a mixture of the two were added at the pre-intercooler position to keep the same charge and cooling of the original rich mixture, reduce BSFC and increase ITE, and promote combustion. The methanol/water mixing volume ratios of different fuel injection strategies were compared to find the best balance between fuel consumption, performance, and emission trends. By simulating the combustion mechanism of methanol, water, and diesel mixed through the Chemkin system, the ignition delay, temperature change, and the generation rate of the hydroxyl group (−OH) in the reaction process were analyzed. Furthermore, the performance and emission of the engine were analyzed in combination with the actual experiment process. This paper studied the application of different concentration ratios of the water–methanol–diesel mixture in engines. Five concentration ratios of water–methanol blending were injected into the engine at different injection ratios at the pre-intercooler position, such as 100% methanol, 90% methanol/10% water, 60% methanol/40% water, 30% methanol/70% water, 100% water was used. With different volume ratios of premixes, the combustion rate and combustion efficiency were affected by droplet extinguishment, flashing, or explosion, resulting in changes in combustion temperature and affecting engine performance and emissions. In this article, the injection carryout at the pre-intercooler position of the intake port indicated thermal efficiency increase and a brake specific fuel consumption rate decrease with the increase of water–methanol concentration, and reduce CO, UHC, and nitrogen oxide emissions. In particular, when 60% methanol and 40% water were added, it was found that the ignition delay was the shortest and the cylinder pressure was the largest, but the heat release rate was indeed the lowest.

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High Efficiency Energy Conversion System Based on Modified Brayton Cycle

ASME 2005 Internal Combustion Engine Division Spring Technical Conference ◽

10.1115/ices2005-1051 ◽

2005 ◽

Author(s):

Anatoli A. Borissov ◽

Alexander A. Borissov ◽

Kenneth K. Kramer

Keyword(s):

High Efficiency ◽

Fuel Efficiency ◽

Brayton Cycle ◽

Positive Displacement ◽

Heat Engines ◽

Current State ◽

Technological Advances ◽

First Results ◽

Power Generation Systems ◽

Vortex Combustion

Each year, the users in the U.S. alone spend over $100 billion on various type of engines to produce power — electrical, mechanical, and thermal. Despite technological advances, most all of these power generation systems have only been fine tuned: the engine efficiencies may have been improved slightly, but the underlying thermodynamic principles have not been modified to effect a drastic improvement. The result is that most engines in service today suffer from two major problems: low fuel efficiency and emission of high levels of polluting gases in the exhaust gases. The current state of propulsion engines or distributed generation technologies using heat engines shows an average efficiency of between 20% and 40%. These low efficiencies in a high–cost energy market indicate a great need for more efficient technologies. This paper describes a new method of achieving a very high efficiency, namely optimizing every stage of the thermodynamic process-Brayton cycle. Two modified processes, such as isothermal compression and recuperation, add about 35% efficiency to the conventional Brayton cycle, making 60% efficiency for modified Brayton cycle. By utilizing a positive displacement compressor and expander with a novel vortex combustion chamber and a vortex recuperator, high levels of efficiency with low emissions and noise are possible. The prototype engine with low RPM and high torque has been built which use continuous combustion of different fuels under a constant pressure. First results of the engine’s components testing are presented.

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