柴油机活塞温度场试验研究及有限元热分析

Finite Element Thermal Analysis and Temperature Field Measurement of Diesel Engine Piston

对改进的ZH1105W型柴油机缩口四角ω燃烧系统,利用热电偶法实测了标定工况下活塞顶面、侧面和内腔共16个特征点的温度。用Pro/E建立活塞几何模型,选取热结构耦合单元,并对模型网格进行了优化,结合试验值对活塞进行热分析计算,得到活塞三维温度场、热应力场和变形。计算结果表明,在标定工况下,活塞最高温度出现在燃烧室喉部达到310.7℃,最大von Mises热应力出现在排气一侧的回油孔顶部,为68.4 MPa,最大热变形量出现在活塞顶面边缘排气口侧,达到0.328 mm,这为活塞的结构改进和优化提供了依据。

For the improved quadrangle combustion chamber of omega shape of the ZH1105W diesel engine, the sixteen characteristic temperatures of the piston on top, outside and inside were measured under the rated power condition through thermocouple contact process., The geometrical model of the piston was set up with the Pro/E software, the thermal structure of coupling unit was selected, and the model meshing was optimized. The three-dimensional temperature field, stress and distortion of the piston are acquired by combining testing data and finite element calculation. The temperature distribution results of the model under the rated power condition indicate that the highest temperature is 310.7℃ at the throat of the combustion chamber, the highest von Mises thermal stress is 68.4 MPa and takes place at outlet hole of piston, and the largest thermal distortion is 0.328 mm and takes place at the head brim near exhaust port, which provides supports for the further optimization of piston.