A STUDY ON THE COMBUSTION CHARACTERISTICS ACCORDING TO THE SHAPE OF ENGINE PISTON HEAD

In this work, the combustion characteristics of a direct injection compression ignition (DICI) engine fueled with diesel using the different piston bowl geometries together with varying injection rate-shapes were investigated. We can change the piston surface to compare the turbulence kinetic energy. So we use three geometries of piston bowl for comparing. Set the geometry as deep concave round, shallow concave round and double concave round. It can be found the double concave round geometry, which has the better geometry, gives the highest turbulence kinetic energy (TKE) and this resulted in two peak heat-releases, with a primary peak heat-release during the premixed combustion phase and a secondary peak heat-release during the mixing– controlled combustion phase. So this paper will investigate the bowl geometries that generate high KTEs as well as the fuels with lower viscosities. Generally we can through change the geometry for improving the air/fuel ratio for decreasing the exhaust emissions.