Performance analysis of a two-stroke spark ignition engine by computer simulation

Economic and effective use of internal combustion engines is becoming more and more important. Therefore, intense studies about increasing the performance of the engines are performed. Determination of the engine performance has been done in two stages. At the first stage, the performance of the engine still in a draft form is determined through the cycle analysis in a theoretical way by using a mathematical model. At this stage each parameter of the engine is changed and its effect on engine characteristics are determined. At the second stage, experimental studies are done in accordance with theoretical work. Due to the enormous advances in computer technology, the solutions of the mathematical models formed in engineering have become easier and theoretical work has gained greater importance. Characteristic values such as cylinder pressure and temperature, mean indicated pressure, mean effective pressure and thermal efficiency can be calculated by using the generated simulation programs. However, the validity of the results depends on attending of the different operating conditions and the parameters which will determine the appropriate performance into a mathematical model in a realistic approach. In this study, a computer program was developed to simulate the performance of a two-stroke spark ignition engine by using MATLAB/SIMULINK programming language.Characteristic values such as cylinder pressure and temperature, mean indicated and effective pressure, effective power, effective torque and thermal efficiency were calculated and their graphics were drawn depending on the engine speed and the angle of crankshaft by using the generated simulation program. Results are compatible with the test results.Key Words: Spark ignition engine, simulation, modeling, two-strokeengine, engine performance