活塞热冲击问题理论分析

Theoretical Study on Thermal Shock of a Piston

摘要本文依据活塞受热特点,以R M Morse和H Feshbach提出的双曲线型导热方程为基础,建立了一种分析活塞热冲击问题的数学模型,并利用拉普拉斯变换对其进行求解.文中以PA6-280柴油机活塞为例,对热冲击期间活塞表面一层内的温度及热应力的变化规律做了较详细的分析.计算结果表明:活塞在热冲击期间表现的温度及热应力的动力学效应是必须加以考虑的.

According to the thermal loading conditions of piston, a mathematical model for piston thermal shock problem was set up on the basis of the hyperbolic conduction equation proposed by R. M. Morse and H. Feshbach, and was solved by Laplace transform method. The change rate of the temperature and thermal stress in the surface layer of the piston were analyzed and discused in detail during the thermal shock. It was shown that the dynamic effect of the temperature and thermal stress of piston must be considered during thermal shock.