Thermal Analysis of Piston for the Influence on Secondary motion

The gas force due to the combustion in the cylinder of an IC engine will cause the piston to move with primary motion and secondary motion. The primary motion of the piston from TDC to BDC is linear in nature. This motion is desired for translation of motion of engine components. Secondary motion is due to the transverse motion of the piston while piston moving from TDC to BDC and vice-versa. The secondary motion of the piston is considered as the main source for the piston slap, which in turn causes the impact on the cylinder walls resulting in engine vibration and noise. In the present study, an effort is made to understand the effect of the thermal load, generated by the combustion of fuel inside the cylinder, on the piston deformation and thermal stresses induced in piston. This deformation of the piston inside the cylinder causes the gap between the cylinder and piston to vary and also the piston to move transversely along with impact forces. The transverse motion of the piston in the cylinder is observed experimentally by measuring the gap between piston and cylinder at thrust side load condition. Finite element analysis (FEA) is considered as one of the best numerical tools to model and analyze the physical systems. FEA is carried out to find the piston deformation due to thermal load on the piston for the temperature data obtained from experiments. The three dimensional piston is modeled in CATIA V5 R19 and analyzed in ANSYS 12 solver. The simulation results are used to predict effect of temperature on piston deformation and its secondary motion which are the principal source of engine vibration