Effect of Exhaust Valve Timing on Gasoline Engine Performance and Hydrocarbon Emissions

2004 ◽  
Author(s):  
Stanislav V. Bohac ◽  
Dennis N. Assanis
Keyword(s):  
Gasoline Engine ◽  
Engine Performance ◽  
Exhaust Valve ◽  
Hydrocarbon Emissions ◽  
Valve Timing

PERFORMANCE INVESTIGATION OF AN SI ENGINE WITH VARIABLE VALVE TIMING AND LIFT BASED ON A MAGNETO-RHEOLOGICAL VALVE

2016 ◽  
Vol 40 (5) ◽  
pp. 749-760 ◽  
Author(s):  
Yaojung Shiao ◽  
Wen-Hsin Cheng
Keyword(s):  
Degrees Of Freedom ◽  
High Efficiency ◽  
Gasoline Engine ◽  
Engine Performance ◽  
Valve Lift ◽  
Valve Timing ◽  
Si Engine ◽  
Timing Simulation ◽  
Magneto Rheological ◽  
Variable Valve

Cylinder valve with variable timing and variable lift is a potential technology to improve engine performance. This research studied cylinder dynamics of a spark-ignition (SI) engine equipped with a new full variable valve system (VVS) based on an innovated magneto-rheological (MR) technology. An MR valve block was combined with a conventional inlet valve in this MR VVS. The study obtained many patterns of valve opening/closing by controlling current to the MR VVS, which controlled the MR fluid flowing through magnetic plate block. Magnetic simulations were performed for the new MR VVS to investigate the relationships among MR valve displacement, valve lift, and valve timing. Simulation results showed that the MR VVS provided high degrees of freedom of valve timing and lift for gasoline engine to produce different torque modes and high engine efficiency. The abilities of this MR VVS to become essential technique of high-efficiency engine were confirmed in the results.

Performance Tuning of an IC Engine Based on Pressure Wave Propagation With a Continuously Variable Exhaust Runner Length and Exhaust Valve Timing System

2017 ◽  
Author(s):  
V. Gajula ◽  
S. Bari
Keyword(s):  
Pressure Wave ◽  
Engine Performance ◽  
Exhaust Valve ◽  
Performance Tuning ◽  
Valve Timing ◽  
Ic Engine ◽  
Scavenging Effect ◽  
Varying Length ◽  
Valve Opening ◽  
Positive Effect

The momentum of exhaust gas flowing out of the valve creates a pressure wave which can have a positive effect on the evacuation of gases. This concept is known as wave tuning, utilizes the sub-atmospheric pressure waves in the runner to evacuate more exhaust gases. When tuned precisely by varying length and/or exhaust valve timing in such a way that the wave returns in accordance to the exhaust valve opening, it creates a scavenging effect and this improves the engine performance. In this research both exhaust runner length and valve duration have been changed to arrive the sub-atmospheric wave at exhaust valve to improve the performance of the engine using Ricardo WAVE software. It was found that varying the exhaust valve timing managed to improve the torque by 1–3% at different rpm. However, varying both length and timing improved the toque 7–10% at lower speed and 3–6% at higher rpm.

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.

Economy and emission characteristics of the optimal dilution strategy in lean combustion based on GDI gasoline engine equipped with prechamber

2021 ◽  
Vol 13 (12) ◽  
pp. 168781402110381
Author(s):  
Li Wang ◽  
Zhaoming Huang ◽  
Wang Tao ◽  
Kai Shen ◽  
Weiguo Chen
Keyword(s):  
Fuel Economy ◽  
Gasoline Engine ◽  
Direct Injection ◽  
Engine Performance ◽  
Gasoline Direct Injection ◽  
Dilution Ratio ◽  
Lean Combustion ◽  
Excess Air ◽  
Combustion Phase ◽  
Hc Emissions

EGR and excess-air dilution have been investigated in a 1.5 L four cylinders gasoline direct injection (GDI) turbocharged engine equipped with prechamber. The influences of the two different dilution technologies on the engine performance are explored. The results show that at 2400 rpm and 12 bar, EGR dilution can adopt more aggressive ignition advanced angle to achieve optimal combustion phasing. However, excess-air dilution has greater fuel economy than that of EGR dilution owing to larger in-cylinder polytropic exponent. As for prechamber, when dilution ratio is greater than 37.1%, the combustion phase is advanced, resulting in fuel economy improving. Meanwhile, only when the dilution ratio is under 36.2%, the HC emissions of excess-air dilution are lower than the original engine. With the increase of dilution ratio, the CO emissions decrease continuously. The NOX emissions of both dilution technologies are 11% of those of the original engine. Excess-air dilution has better fuel economy and very low CO emissions. EGR dilution can effectively reduce NOX emissions, but increase HC emissions. Compared with spark plug ignition, the pre chamber ignition has lower HC, CO emissions, and higher NO emissions. At part load, the pre-chamber ignition reduces NOX emissions to 49 ppm.

Turbocharger-Design Effects on Gasoline-Engine Performance

2005 ◽  
Vol 127 (3) ◽  
pp. 525-530 ◽  
Author(s):  
Theodosios Korakianitis ◽  
T. Sadoi
Keyword(s):  
Steady Flow ◽  
Mass Flow ◽  
Gasoline Engine ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Thermodynamic Cycle ◽  
Final Choice ◽  
Design Point ◽  
Theoretical Considerations ◽  
Flow Experiments

Specification of a turbocharger for a given engine involves matching the turbocharger performance characteristics with those of the piston engine. Theoretical considerations of matching turbocharger pressure ratio and mass flow with engine mass flow and power permits designers to approach a series of potential turbochargers suitable for the engine. Ultimately, the final choice among several candidate turbochargers is made by tests. In this paper two types of steady-flow experiments are used to match three different turbochargers to an automotive turbocharged-intercooled gasoline engine. The first set of tests measures the steady-flow performance of the compressors and turbines of the three turbochargers. The second set of tests measures the steady-flow design-point and off-design-point engine performance with each turbocharger. The test results show the design-point and off-design-point performance of the overall thermodynamic cycle, and this is used to identify which turbocharger is suitable for different types of engine duties.

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