scholarly journals Effect of Divided Exhaust Period in a High Efficiency TGDI Engine

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6343
Author(s):  
Heechang Oh ◽  
Dongwon Jung ◽  
Jinwook Son ◽  
Soohyung Woo ◽  
David Roth ◽  
...  
Keyword(s):  
Thermal Efficiency ◽  
High Efficiency ◽  
Gasoline Engine ◽  
Engine Performance ◽  
Design Parameters ◽  
Engine Simulation ◽  
Spot Area ◽  
Gas Recirculation ◽  
Off Time ◽  
Dynamometer Test

The divided exhaust period (DEP) concept was applied to a high-efficiency gasoline engine and its impact on various engine performance aspects were investigated. To this end, key design parameters of DEP components were optimized through 1-D engine simulation. The designed DEP components were fabricated and experimental verification was performed through an engine dynamometer test. The developed DEP engine shows suitable performance for electrified vehicles, with a maximum thermal efficiency of 42.5% as well as a wide sweet spot area of efficiency over 40%. The improvement in thermal efficiency was mainly due to a reduction in pumping loss. Notably, the reduction in pumping loss was achieved under high exhaust gas recirculation (EGR) flow conditions, where further improvements in fuel consumption could be achieved through a synergistic combination of DEP implementation and high dilution combustion. Furthermore, a significantly improved catalyst light-off time, uncharacteristic in turbocharged engines, was confirmed through a simulated cold-start catalyst heating engine test.

scholarly journals A Comparison of Ethanol, Methanol, and Butanol Blending with Gasoline and Its Effect on Engine Performance and Emissions Using Engine Simulation

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1322
Author(s):  
Simeon Iliev
Keyword(s):  
Alternative Fuels ◽  
Fossil Fuels ◽  
Gasoline Engine ◽  
Engine Performance ◽  
Exhaust Emissions ◽  
Engine Simulation ◽  
Engine Model ◽  
Fuel Blends ◽  
Performance And Emissions ◽  
Blended Fuels

Air pollution, especially in large cities around the world, is associated with serious problems both with people’s health and the environment. Over the past few years, there has been a particularly intensive demand for alternatives to fossil fuels, because when they are burned, substances that pollute the environment are released. In addition to the smoke from fuels burned for heating and harmful emissions that industrial installations release, the exhaust emissions of vehicles create a large share of the fossil fuel pollution. Alternative fuels, known as non-conventional and advanced fuels, are derived from resources other than fossil fuels. Because alcoholic fuels have several physical and propellant properties similar to those of gasoline, they can be considered as one of the alternative fuels. Alcoholic fuels or alcohol-blended fuels may be used in gasoline engines to reduce exhaust emissions. This study aimed to develop a gasoline engine model to predict the influence of different types of alcohol-blended fuels on performance and emissions. For the purpose of this study, the AVL Boost software was used to analyse characteristics of the gasoline engine when operating with different mixtures of ethanol, methanol, butanol, and gasoline (by volume). Results obtained from different fuel blends showed that when alcohol blends were used, brake power decreased and the brake specific fuel consumption increased compared to when using gasoline, and CO and HC concentrations decreased as the fuel blends percentage increased.

Development of High Efficiency Gasoline Engine with Thermal Efficiency over 42%

2017 ◽  
Author(s):  
Byeongsoek Lee ◽  
Heechang Oh ◽  
SeungKook Han ◽  
SooHyung Woo ◽  
JinWook Son
Keyword(s):  
Thermal Efficiency ◽  
High Efficiency ◽  
Gasoline Engine

Application of Over-Expansion Cycle to a Larger Gasoline Engine With Late-Closing of Intake Valves

2002 ◽  
Author(s):  
Seiichi Shiga ◽  
Kenji Nishida ◽  
Shizuo Yagi ◽  
Youichi Miyashita ◽  
Yoshiharu Yuzawa ◽  
...  
Keyword(s):  
Compression Ratio ◽  
Thermal Efficiency ◽  
Gasoline Engine ◽  
Engine Performance ◽  
Mechanical Efficiency ◽  
Expansion Ratio ◽  
Brake Thermal Efficiency ◽  
Gasoline Engines ◽  
Cylinder Test ◽  
Test Engine

This paper presents further investigation into the effect of over-expansion cycle with late-closing of intake valves on the engine performance in gasoline engines. A larger single-cylinder test engine with the stroke volume of 650 cc was used with four kinds of expansion ratio (geometrical compression ratio) from 10 to 25 and four sets of intake valve closure (I.V.C.) timings from 0 to 110 deg C.A. ABDC. Late-closing has an effect of decreasing the pumping work due to the reduction of intake vacuum, althogh higher expansion ratio increases the friction work due to the average cylinder pressure level. Combining the higher expansion ratio with the late-closing determines the mechanical efficiency on the basis of these two contrastive effects. The indicated thermal efficiency is mostly determined by the expansion ratio and little affected by the nominal compression ratio. The value of the indicated thermal efficiency reaches to 48% at most which is almost comparable with the value of diesel engines. The improvement of both indicated and brake thermal efficiency reaches to 16% which is much higher than ever reported by the authors. A simple thermodynamic calculation could successfully explain the behavior of the indicated thermal efficiency. The brake thermal efficiency could also be improved due to the increase in both mechanical and indicated efficiencies.

Minimum Backpressure Wastegate Control for a Boosted Gasoline Engine With Low Pressure External EGR

2016 ◽  
Author(s):  
Shima Nazari ◽  
Anna Stefanopoulou ◽  
Jason Martz
Keyword(s):  
Gasoline Engine ◽  
Direct Injection ◽  
Fuel Efficiency ◽  
Engine Performance ◽  
Low Pressure ◽  
Gasoline Direct Injection ◽  
Efficiency Gain ◽  
Engine Simulation ◽  
Trade Offs ◽  
Torque Response

Turbocharging and downsizing (TRBDS) a gasoline direct injection (GDI) engine can reduce fuel consumption but with increased drivability challenges compared to larger displacement engines. This tradeoff between efficiency and drivability is influenced by the throttle-wastegate control strategy. A more severe tradeoff between efficiency and drivability is shown with the introduction of Low-Pressure Exhaust Gas Recirculation (LP-EGR). This paper investigates and quantifies these trade-offs by designing and implementing in a one-dimensional (1D) engine simulation two prototypical throttle-wastegate strategies that bound the achievable engine performance with respect to efficiency and torque response. Specifically, a closed-wastegate (WGC) strategy for the fastest achievable response and a throttle-wastegate strategy that minimizes engine backp-pressure (MBWG) for the best fuel efficiency, are evaluated and compared based on closed loop response. The simulation of an aggressive tip-in (the driver’s request for torque increase) shows that the wastegate strategy can negotiate a 0.8% efficiency gain at the expense of 160 ms slower torque response both with and without LP-EGR. The LP-EGR strategy, however offers a substantial 5% efficiency improvement followed by an undesirable 1 second increase in torque time response, clarifying the opportunities and challenges associated with LP-EGR.

scholarly journals Investigation of the Gasoline Engine Performance and Emissions Working on Methanol-Gasoline Blends Using Engine Simulation

2020 ◽  
Author(s):  
Simeon Iliev
Keyword(s):  
Fuel Consumption ◽  
Gasoline Engine ◽  
Engine Performance ◽  
Specific Fuel Consumption ◽  
Injection System ◽  
Si Engine ◽  
Engine Simulation ◽  
Fuel Blends ◽  
Performance And Emissions ◽  
The One

The aim of this study is to develop the one-dimensional model of a four-cylinder, four-stroke, multi-point injection system SI engine and a direct injection system SI engine for predicting the effect of various fuel types on engine performances, specific fuel consumption, and emissions. Commercial software AVL BOOST was used to examine the engine characteristics for different blends of methanol and gasoline (by volume: 5% methanol [M5], 10% methanol [M10], 20% methanol [M20], 30% methanol [M30], and 50% methanol [M50]). The methanol-gasoline fuel blend results were compared to those of net gasoline fuel. The obtained results show that when methanol-gasoline fuel blends were used, engine performance such as power and torque increases and the brake-specific fuel consumption increases with increasing methanol percentage in the blended fuel.

Optimization of the intake port shape for a five-valve gasoline engine

2001 ◽  
Vol 215 (6) ◽  
pp. 739-746 ◽  
Author(s):  
K Lee ◽  
C Lee ◽  
Y Joo
Keyword(s):  
High Efficiency ◽  
Gasoline Engine ◽  
Three Dimensional ◽  
Design Guidelines ◽  
Design Parameters ◽  
Computer Assisted ◽  
Intake Port ◽  
Port Design ◽  
Visualization Experiments ◽  
Valve Engine

For the development of a high efficiency gasoline engine, the optimization of the intake port shape for a five-valve engine has been studied. Intake multivalve cylinder heads were manufactured by using a three-dimensional computer-assisted design program, and steady state flow experiments and flow visualization experiments have been performed with these cylinder heads. The five-valve engines, which have larger valve opening areas, have larger intake flowrates and higher tumble ratios than the four-valve engines. The effects of intake port design parameters of a five-valve engine on the intake flowrate and tumble were studied, and the design guidelines for the five-valve engines were established.

Thermodynamic Considerations Regarding the Use of Exhaust Gas Recirculation for Conventional and High Efficiency Engines

2017 ◽  
Vol 139 (9) ◽  
Author(s):  
Jerald A. Caton
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Convective Heat Transfer ◽  
Thermal Efficiency ◽  
High Efficiency ◽  
Convective Heat Transfer Coefficient ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Gas Recirculation

During the last several decades, investigations of the operation of internal combustion engines utilizing exhaust gas recirculation (EGR) have increased. This increased interest has been driven by the advantages of the use of EGR with respect to emissions and, in some cases, thermal efficiency. The current study uses a thermodynamic engine cycle simulation to explore the fundamental reasons for the changes of thermal efficiency as functions of EGR. EGR with various levels of cooling is studied. Both a conventional (throttled) operating condition and a high efficiency (HE) operating condition are examined. With no EGR, the net indicated thermal efficiencies were 32.1% and 44.6% for the conventional and high efficiency engines, respectively. For the conditions examined, the cylinder heat transfer is a function of the gas temperatures and convective heat transfer coefficient. For increasing EGR, the gas temperatures generally decrease due to the lower combustion temperatures. For increasing EGR, however, the convective heat transfer coefficient generally increases due to increasing cylinder pressures and decreasing gas temperatures. Whether the cylinder heat transfer increases or decreases with increasing EGR is the net result of the gas temperature decreases and the heat transfer coefficient increases. For significantly cooled EGR, the efficiency increases partly due to decreases of the heat transfer. On the other hand, for less cooled EGR, the efficiency decreases due at least partly to the increasing heat transfer. Two other considerations to explain the efficiency changes include the changes of the pumping work and the specific heats during combustion.

scholarly journals Prototype of Disc Brake Dynamometer

2020 ◽  
Author(s):  
Pakkip Kraisoda
Keyword(s):  
Thermal Efficiency ◽  
Performance Test ◽  
Gasoline Engine ◽  
Engine Performance ◽  
Performance Standard ◽  
Engine Torque ◽  
Single Cylinder ◽  
Disk Brake ◽  
Single Cylinder Engine ◽  
Brake Dynamometer

Abstract This paper presents the design and test of prototype of Disk Brake Dynamometer of Single-cylinder engine performance standard Brake horsepower with water using the Honda GX-200 four-stroke 196 cm3 gasoline engine, 1-cylinder gasohol 95 fuel. The experiment result showed that the Prototype of Disk brake Dynamometer maximum engine torque was 11.58 N m at 2500 rpm. The maximum power of engine was 3.29 kW at 3000 rpm and maximum thermal efficiency of engine brake was 25.36% at 2500 rpm. When being compared the performance of a standard single-cylinder engine performance test with the all-purpose gasoline engine Honda GX-200 1-stroke 4-stroke 196 cm3 gasohol 95, it was found that Maximum engine torque was less than 5.39%, the maximum engine power was higher than 2.49%, the maximum fuel consumption of the engine was higher than 10% and the maximum thermal efficiency of the engine was higher than 2.39%.

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