Indian Journal of Science and Technology

Abstract

Objective: This work mainly aims to investigate the effect of design variables on numerical thermal analysis of a marine diesel engine piston. Method: Two different design variables are considered in this study. The first design variable to be investigated is piston head geometry and the effects of its modification on temperature distribution of a marine diesel engine piston are studied. Three different cases are studied and the first case is taken for a bowl piston head which is considered the reference case. A flat and a domed piston head are studied as second and third cases. Findings: The numerical thermal analysis is performed for these three cases and the results show that flat top piston is less affected by the combustion with maximum temperature range of 714.86 K-679 K. On the other hand, the results show that domed piston top is exposed to the highest level of temperature ranging from 727.89 K to 690.57 K. The second design variable studied is cooling gallery position and the effect of its axial movement on temperature distribution. Application: Two positions in the axial direction are taken which are obtained by moving the cooling gallery in increment of 3mm axially towards the piston head in each case. Conclusion: Numerical thermal analysis results show that when the cooling gallery is nearer to the piston head surface, the piston surface temperature will get less. It is also shown that the range of referenced bowl piston top temperature is decreased from 713.91 K -678.55 K to 708.4 K-673.38 K when oil cooling gallery is moved by increment of 6mm axially towards piston head.

Keywords: Piston Head, Marine Diesel Engine, Cooling Gallery and Thermal Analysis