Finite Element Analysis Of Temperature And Stress Of A Diesel Engine Piston

With the development of science and technology,the internal combustion engine is gradually developing towards high power,low emission and low fuel consumption.As a very important part of the internal combustion engine,the piston is always in contact with the high temperature gas,which is subjected to very large heat load and mechanical load.So it is necessary to know the temperature and stress of the piston.In this paper,the diesel engine was analyzed by finite element method,which belongs to V diesel engine.First of all,the working process of the diesel engine was simulated by GT-Power software,and meet design requirements.The thermal boundary condition of the piston was determined by empirical formula,then the steady and transient temperature field was calculated by using ANSYS Workbench.The results showed that the temperature of the head is relatively higher,and the temperature gradient of each part is larger,while the skirt temperature is relatively stable.Secondly,the thermal stress field,mechanical stress field and coupling stress field was analyzed and calculated.The results showed that the effect of thermal stress on piston is greater than that of piston skirt.And the maximum area mainly concentrated in the piston head,the main reason is the large temperature gradient.The distribution of the coupling stress field of the piston is close to the thermal stress field distribution,and the stress field of the piston skirt is always stable,and there is not much fluctuation.Finally,the structure of the cooling cavity of the piston was studied,which explored the effects of different cooling methods on the heat load of the piston,including the temperature,thermal stress and thermal deformation.The results showed that the cooling chamber is very important to reduce the heat load of the head,and bottom spray cooling effect is very weak.Based on the analysis and calculation of diesel engine piston,the piston can basically meet the design requirements,and ensure the normal operation of the diesel engine.But the stress should be paid special attention to the oil passage of the inner cooling oil chamber.