DefinePK

Abstract

In the present work, an attempt is made to reduce scavenging problems by developing a new model of two-stroke spark-ignition engine. This model allows a flow of fresh air through intake valves positioned at the bottom of the cylinder and exit of burnt gases through exhaust ports situated at the top of cylinder. The exhaust ports are closed by the piston as it moves towards bottom of the cylinder following which gasoline is injected minimizing the possibility of mixing of fuel with outgoing exhaust gases. During expansion the piston unravels the exhaust ports and the burnt gases escape to the atmosphere due to pressure difference. Due to low density at high temperatures, the exhaust gases naturally rise against the direction of gravity reducing the possibility of mixing with incoming fresh air. Further, a comparative study of fuel distribution inside the cylinder has shown greater distribution when injection takes place against gravity than along gravity, which promotes cleaner combustion. The combustion analysis is done using Diesel-RK software and flow analysis is done using ANSYS FLUENT.