Abstract: Flame front surface area is theoretically analyzed for a spark-ignition engine, having hemispherical shaped combustion chamber and flat head spark ignition engine with two spark plugs located axis symmetrically on cylinder head, between cylinder axis and cylinder wall. A computer code is developed based on purely geometric consideration of the flame development process in combustion chamber on geometric features of the flame front. A hemispherical combustion chamber, also known as the HEMI, has a combustion chamber in the shape of a half sphere. The hemispherical combustion chamber has an advantage of cross flow design that allows the engine to breathe better. This is to give some turbulence to the engine. The hemispherical combustion chamber generates more power as the air does not have to turn at right angles and the resistance to its motion is less. The key advantage of a hemispherical combustion chamber is that its surface area to volume ratio is the least in the category as compared to other designs like flat head, wedge heads, etc. and therefore they have a superior thermal efficiency than other engines. Also, as the valves are located cross-wise, the valves can be made large resulting in better breathing of the engine The effects of the stroke/bore (S/B) ratio on the performance parameters of hemispherical head engine having dual-spark ignition (DSI) were investigated theoretically by using a two zone thermodynamic cycle model. The engine performance parameters, i.e., engine power, indicated mean effective pressure, specific fuel consumption, and thermal efficiency, were computed for various conditions. The obtained results for DSI operation have been compared to those of a single-spark-ignition (SSI) condition for both hemispherical cylinder head spark ignition engine and flat head spark ignition engine.
Keywords: spark ignition engine, single-spark-ignition, dual-spark ignition.
Title: Analytical Study of Flame Front Geometry for Gasoline Powered Engine
Author: Anil Kumar, Anand Solanki, Prem Shankar Sahu
International Journal of Mechanical and Industrial Technology
ISSN 2348-7593 (Online)
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