Thermal analysis of a liquid-petroleum-liquid injection engine piston using the inverse heat conduction method

Abstract

An efficient method utilizing the concept of inverse heat conduction is presented for the thermal analysis of pistons based on application to a liquid-petroleum-liquid injection (LPLI) engine piston. An inverse heat conduction problem is established in the form of an optimization problem. In the optimization problem, the convection heat transfer coefficient (HTC) on the combustion-side surface of the piston is defined as the design variable, while the error between the measured and analysed temperatures is defined as the objective function. For the optimization, two consecutive steps consisting of an axisymmetric and a three-dimensional problem are presented in order to reduce computation time and to obtain stable convergence. The optimum distribution of the HTC at the top surface of the piston is successfully determined through a numerical implementation. The temperature obtained via an analysis using the optimum HTC is compared with the measured temperature, and reasonable agreement is obtained. The present method can be effectively utilized to analyse the temperature distribution of engine pistons.