内燃机活塞内冷油腔振荡冷却特性的模拟研究

Simulation Study on Oscillating Cooling Characteristics in Piston Oil Cooling Gallery of Internal Combustion Engines

利用CLSVOF方法和ALE动网格技术,开展内燃机活塞内冷油腔振荡冷却特性的模拟研究。采用响应面分析方法,研究了结构参数与机油填充率对内冷油腔壁面平均温度的影响规律,并结合多目标遗传优化算法获得了最优的结构参数和机油填充率方案。计算结果表明,随着内冷油腔高度增加,壁面平均温度逐渐降低;随着油腔上壁面宽度增加,壁面平均温度先降低后升高;机油填充率对油腔壁面温度影响的贡献率大于油腔结构;最优方案的壁面平均温度CFD计算值比原机降低8℃,与多目标遗传优化的预测结果误差小于1%。

Oscillating cooling characteristics in piston oil cooling gallery of internal combustion engines were simulated by using CLSVOF method and ALE dynamic grid technique.The influence law of structure parameters and oil filling rate to the average temperature of oil gallery was studied by analyzing response surface method.The optimal structure parameters and oil filling rate were acquired by combining with MOGA method.The calculation results show that the average temperature of oil gallery wall reduces with the height of oil cooling gallery raising;the average temperature of oil cooling gallery wall reduces after first decreases with the length of oil gallery top surface increasing;the contribution rate of oil filling rate is greater than oil gallery structure in reducing average temperature of wall;the optimal case reduces average temperature of original machine wall by 8℃ and the calculation error of the optimal results and calculating result is less than 1%.