Research Of Thermal Loading About Piston Under Start Working Condition

The thermal shock of I. C. E engines and components is more serious with the improving of strengthen technical target, especially under such conditions as the startup frequent, load break, startup under low temperature, etc.In this paper the thermal shock on piston, which is one of the heated parts of zl75F2-diesel engine is selected as investigated subject. The thermal shock test has been carried out in the thermal fatigue simulation test stand developed. Simulation is carried through FEA software ANSYS, piston' s thermal behavior under different shock mode is simulated during engine' s cold start working condition; suitable boundary setting for piston is put forward. Compare the simulation results to the test results, the temperature field and stress field can be got which are quite close to the really thermal shock situation under start behavior of engine. Boundary condition setting is discussed. The special law of the temperature field and stress field has been got under the different temperature start. The above research results of theory and test make a contribution to the study on the thermal damage of the piston and the reliability of start working research of engine.Some conclusion can be obtained:1. Temperature fluctuation of the piston in each cycle of engine working can be ignored under start working condition.2. The boundary condition is important in simulation.3. The lower temperature of the engine start working, the thermal stress is higher.