Thermal analysis of si-engine using simplified finite element model

Abstract

Simplified finite element model of spark ignition (Si) engine to analyze combustion heat transfer is presented. The 2D model is made up with main features of engine including combustion chamber, valves, manifold, cylinder body, piston head and cooling jacket, all projected at the cross section of the cylinder. The model was discretized with 2D thermal elements of global length 0.001. The fuel type is gasoline. Internal nodal temperature of cylinder body is defined as 2100 degrees C to represent occurrence of gasoline combustion. The presence of cooling is modeled by assigning convection coefficient on cooling jacket. Material information and isotropic material properties are taken from published report. The transient heat transfer analysis is done for the instant of combustion. The model is validated by comparing the computed maximum temperature at the piston surface with the published result. The computed temperature gradient at the crucial parts are plotted and discussed. It has been found that the critical component likely suffered from thermal fatigue was the exhaust port near the cylinder head and the materials used to construct the engine parts strongly influenced the temperature distribution in the engine. The model is capable to analyze heat transfer in the engine reasonably and efficiently.