增压柴油机活塞内冷油道对热负荷影响的研究

摘要

The finite element analysis was used to analyze the effect of the internal oil gallery on the temperature, stress and deformation distributions of a turbocharged diesel engine piston.The reasonable boundary conditions of the oil gallery were achieved by the CFD simulation.Piston temperatures were measured by using the hardness plug to verify the simulation results.The finite element analysis results show that the oil gallery can reduce the piston top temperature by nearly 43 ℃, and that a reasonable location of the oil gallery can effectively reduce local high temperature and stress.Moving the location of the oil gallery up or down by 5 mm can affect the top temperature most, reducing or increasing by around 10 ℃, and can increase the maximum piston stress value by 7 to 11 MPa.Changing the oil gallery location mainly influences the value of piston deformation, but has a little effect on the distribution of piston deformation.%针对某增压柴油机,使用有限元法研究了内冷油道对活塞温度分布、应力分布和变形分布的影响.为保证边界条件的合理性,通过计算流体力学(CFD)软件模拟计算得到内冷油道的边界条件.采用硬度塞法实测活塞若干点的温度值,验证了模拟计算结果的合理性.有限元计算结果表明:在活塞上加开内冷油道可以使其顶部温度降低约43 ℃;合理的内冷油道位置可以有效降低局部的高温和应力,当活塞内冷油道位置轴向移动5 mm时对活塞顶部温度影响最大,可使其温度变化幅度达10 ℃左右,最大应力值增加7~11 MPa.内冷油道位置的改变主要影响各部分变形的大小,对其分布规律影响不大.