Combustion chamber geometry effects in spark ignition engine exhaust emissions

Abstract

The paper presents experimental results showing the effect of hemispherical, cylindrical and oval bowls-in-piston on exhaust gases within the cylinder of spark ignition engines. Results indicate that bowls increase both heat transfer and flame speed. Consequently, flame ability must become wide to reduce both engine emissions and cycle combustion variability. Hemispherical effect ranked first on hydrocarbon and carbon monoxide emissions, followed by cylindrical then oval. Nitrogen oxides are in opposite direction, with oval ranked first, followed by cylindrical then hemispherical.

Keywords:

• Bowls-in-piston
• exhaust gases
• SI engine
• operating parameters
• Ricardo engine
• flat combustion chamber
• piston crown
• flame speed
• cycle combustion variability and turbulence

Additional information

Notes on contributors

H Zefaan

Dr Helmy Zefaan received his BSc in 1981 from Automotive and Tractors Engineering Department, Mataria, Helwan University, Egypt. He received his MSc in 1986 from Automotive and Tractors Engineering Department, Minia College, Minia University, Egypt. In addition he received both License of Low in 1995 and PhD in 1996 in Mechanical Engineering from Cairo University. Moreover he received his consultant degree in the field of Mechanical Equipment and Vehicles in 2004 from Engineering Syndicate, Egypt. He has trained in different countries such as Japan, Turkey, Germany, Romania and Dubai.