Response optimization of four stroke variable compression ratio diesel engine cylinder head with stress analysis

Abstract

The main aim of this work is to predict the design performance based on the stress/strain and behavior of cylinder head under various operating conditions. The effects of engine operating conditions such as combustion gas maximum internal pressure and temperature on the cylinder head have been analyzed. The maximum gas pressure vs crank angle are taken from the experimental set up of a variable compression ratio (VCR) Diesel engine . The analysis was carried out at three different compression ratios like 16.5,17.5,18.5 using a finite element analysis (FEA) software package, which is use to simulate and predict the Von-Mises stresses and strain pattern and thermal distribution of the cylinder head structure .The geometrical modelling was carried out using CATIA and analysis is done on ANSYS software. In this investigation, structural and thermal analysis of the cylinder head highlight several areas of interest. The maximum stress is found not exceeding the material strength of cylinder head, and thus the basic design criteria, namely no yielding and no structural failure under firing load case are satisfied. This steady-state finite element method (FEM) stress analysis can play a very effective role in the rapid prototyping of the cylinder head. The results of the thermo-mechanical analysis show that when the engine is running, the stress in the region is compressive, caused by thermal loading and combustion pressure. The fatigue analysis is carried out to know the factor of safety and life of the cylinder head it indicates maximum life of 1x106 cycles at all compression ratios are determined through finite element analysis. Further response optimization method is employed for the cylinder head by varying the thickness of the head in order to minimize the various stresses and deformation and temperature distribution values