The Study on the Effect of the Piston Shapes through Biodiesel Mixture Combustion in Diesel Engine

^1.3 Division of Mechanical and Automotive Engineering, Kongju National University 1223-24, Cheonan Daero, Seobuk-gu, Cheonan-si, Chungcheongnam-do 331-717, South Korea.
² Department of Mechanical Engineering, University of Malaya.

^* Corresponding author: hmcho@kongju.ac.kr

Abstract

In this work, we studied the combustion characteristics of a direct injection compression ignition (DICI) engine. Diesel uses different cylinder geometry and different injection rate shapes. We can change the piston surface to compare turbulent flow energy and eddy viscosity. So we use three geometric piston bowls for comparison. The geometry is set to a single circle, a double circle and a flat bottom so that the engine combustion characteristics can be improved and the exhaust emissions can be reduced. Therefore, we can find through simulation that a double circular geometry piston with a better geometry has the highest turbulent kinetic energy (TKE) and this results in two peak heat releases with a main peak heat release during premixed combustion. And secondary peak heat release occurs during the mixed controlled combustion phase. This article adopts this geometry. The air-biofuel mixture can be squeezed in two wheels because better vortexing can squeeze the mixture better to improve the mixture. Therefore, this article will examine the bowl-shaped geometries that produce high-KTE and low-viscosity fuels, single-circle geometries, double-circular geometries, and flat base geometries. In general, we can increase the air/fuel ratio by changing the geometry to reduce exhaust emissions.