THERMO-MECHANICAL ANALYSIS OF PISTON OF A FOUR STROKE DIESEL ENGINE

Abstract

Piston is the "heart" of the internal combustion engine and its working is very versatile and dynamic in nature among the other parts of the engine. Piston converts heat and pressure energy liberated by fuel combustion into mechanical works. For smooth running of vehicle, piston should be in proper working condition. In this research, the stress distribution of piston in the actual working condition of the engine was investigated and analyzed. Aluminium alloy (Al 4032) has been selected as piston material for mechanical and thermal analysis. Mechanical analysis, thermal analysis and thermo mechanical analysis has been carried out for the actual working condition of the piston. The parameters used for the analysis of the piston were maximum gas pressure and maximum temperature at the piston head and material properties of piston of the four stroke diesel engine produces brake power of 5.2KW at 1500 rpm. Piston fails generally due to strain produced by mechanical stresses and thermal stresses at the edge of piston head. Analysis of piston has been performed by using boundary conditions, which includes pressure on the piston head during working condition and uneven temperature distribution from the piston head to the skirt. The CAD model of the piston was created by using SOLIDWORKS software. CAD model is then imported into ANSYS software for meshing and simulation purpose. The Finite Element Analysis was performed by using ANSYS 15.0 and various stresses such as maximum principal stresses, Von- Mises stresses, total deflection, total heat flux and thermal strain occurred during working condition were evaluated. The results of the simulation depicts the stresses occurred in piston is within the permissible limit of the piston material and the deformation is well within the tolerance limit.