Diagnostic simulation for measuring the combustion characteristics and the heat transfer coefficient in the cylinder of turbocharged gasoline engines

Heat Transfer experiments were carried out during the engine performance tests of a 4-cylinder 4-stroke turbo-charged gasoline engine. Diagonostic engine simulations to analyse the combustion characteristics in cylinder and heat transfer characteristics of cylinder wall were carried out employing the measured pressure variation in cylinder and cooling water temperature and flowrate. In these simulation, combustion processes were simulated by the Annand's two zone flame propagation model (1). From these simulation we can obtain not only the heat transfer coefficient of cylinder wall but also the flame speed, turbulent burning velocity and flame factor. The results are investigated with respect to engine speed and equivalence ratio. And combustion characteristics of turbocharged engine were compared with those of naturally aspirated engine.