A Study of In-Cylinder Local Heat Transfer Characteristics of a Spark Ignition Engine 931981
In order to verify the possibility of representing the local heat transfer characteristics within the combustion chamber by flow-based zonal modelling, cycle simulation and finite element (FE) analysis for the temperature distribution in the piston and cylinder block were performed. Convective heat transfer coefficient was calculated using flow-based zonal model and compared with that using Woschni's Correlation. Calculated temperature distribution of the piston and the cylinder block showed that the flow- based zonal model is far more logical because of its capability to reflect in-cylinder flow, combustion chamber configuration, and engine operating condition. The shape of isothermal line and the highest temperature region location by flow-based zonal modelling are affected by the magnitude of heat loaded from combustion chamber. The results obtained from Woschni's correlation, however, do not show any change in the isothermal line shape and the highest temperature region location. Judging from the experimental results, flow-based zonal model, the correlations for the instantaneous local heat transfer coefficient, is more reasonable than the Woschni's correlation, the correlations for the instantaneous spatial average heat transfer coefficient from the fact that the former represents experimental data more closely.