High Speed Schlieren Photographic Observation On The Stratified Charge Combustion In A Divided Combustion Bomb Simulator

Abstract

The combustion phenomena of stratified charge combustion in a divided combustion bomb simulator under the initial conditions of room temperature and atmospheric pressure was investigated by using combustion bomb pressure record and high speed schlieren photography in comparison with that of homogeneous charge combustion in the same combustion bomb. For the demonstrative illustration of high speed schlieren photography to show the characteristics of stratified charge combustion and homogeneous charge combustion, four different cases of fuel/air mixture charging combinations were chosen. The results show that stratified charge combustion can reduce its total burning time comparing with the total burning time of homogeneous charge combustion and pressure rise-up of stratified charge combustion is rather faster and higher than that of homogeneous charge combustion. It is also indicated that stratified charge combustion can enhance its leaner inflammability limit than homogeneous charge combustion. The detailed high speed schlieren photography visualize small wrinkled or turbulent flamelets and discrete vorticity associated with flame jet expanding into the main chamber through the connecting orifice between the pre-chamber and the main chamber.