Computer simulation studies on a four stroke cycle spark ignition engine using gasoline and hydrogen as alternative fuels

This paper describes the results of computational studies on a single cylinder four stroke cycle spark ignition engine using Hydrogen as an alternative fuel to petrol. The simulation is done in the professional engine simulation software from AVL Austria named as BOOST. The modeling methodology involves the use of first law of thermodynamics for engine as an open system when valves are open and engine as a closed system when valves are closed. To include the effect of gas exchange in the intake and exhaust manifolds when the valves are open, the modeling is done using Navier -Stokes equations for manifolds. The design parameters are fixed by engine geometry. A matrix was prepared for the operating variables to carry out the simulation. First the data was used as per petrol engine needs, and results for engine performance and emissions characteristics were generated. The operation was revised with data for proposed hydrogen engine and its performance and emissions characteristics were studied. The software gave successful results in both the cases. It was observed that the power output was decreased with hydrogen as an alternative fuel due to lower volumetric efficiency, the brake specific fuel consumption was comparable in both cases due to higher calorific value of hydrogen. The emissions were also reduced with hydrogen as fuel because of no carbon atoms as compared to petrol fuel. No CO emission was produced with hydrogen, there was reduction in NOx emission and also there was drastic reduction in hydrocarbon emissions with hydrogen as fuel. It is proposed that hydrogen can be successfully used in petrol engine as an alternative future fuel.