Experimental Study And Finite Element Simulation On The Strength Of Natural Gas Engine’s Piston

Natural gas engines have emerged under the background of global oil energycrisis and increasingly stringent emissions regulations.For high-power,turbochargednatural gas engines, Its components of combustion chamber,especially forpistons,have been working in very harsh environment.In the work process of the gasengine.pistons have been suffered badly fierce and periodically changed thermal andmechanical loads for they are directly contacting with the high temperature and highpressure gas in combustion chamber.As one of the key conponents of the enginepower output,pistons prone to occur erosion, cracking and other faults in such ahostile working environment,which will seriously affect the stability and reliability ofthe engine.In this paper,thermal and mechanical loads pistons suffered were studiedby experimental study and finite element simulation based on YC6MK natural gasEngine test bench and ANSYS workbench software.Firstly, put up natural gas Engine test bench,and measure the temperature field ofpiston in demarcate condition.Secondly,use Pro/E software to build a full-size three-dimensional model ofpiston,use HyperMesh software to mesh piston model,and import the piston model toANSYS workbench.Then calculate the thermal boundary conditions of piston by thework shown in diagram and the empirical formula and proceed the simulation ofsolving the temperature field of the piston.Comparing with experimental data, adjustthe boundary conditions so that the result is consistent with the experimentaldata.Taking the thermal shock of the high-temperature gas in combustion chamberinto account,calculate the transient temperature field of piston.Finally, on the basis of the steady-state temperature field on the piston,obtain thethermal stress and thermal deformation of the piston.And calculate the mechanicalstress and deformation of the piston on maximum explosion pressure point indemarcate condition,considering with gas pressure and inertia force of the pistonUltimately,calculate the thermal-mechanical coupling stress and deformation of thepiston under the combined action of thermal and mechanical loads. The results can be obtained by analyzing the calculations:in demarcatecondition,the piston of YC6MK natural gas engine has beared great thermal andmechanical loads.The temperature of the first ring groove is so high that lubricantingoil can easily lead to the coke,carbon deposition. Stress concentration occurs at pistonpin snap ring groove.