柴油机流固耦合传热仿真研究

为解决发动机活塞组-缸套-冷却水-机体之间传热边界条件难以确定的问题,尤其是冷却水和缸套、机体之间的流固边界的温度和换热系数,将这几个部件作为一个耦合系统进行传热研究.该系统既包括了流体和固体之间的流动与传热的耦合,也包括了固体与固体之间的耦合传热.利用有限元分析软件的流固耦合计算功能,以所建立的某增压柴油机的流固耦合系统为例进行了仿真计算,得到了耦合系统的温度场和流场.这样把单个零件的传热外边界条件变成内边界,使得传热仿真更合理更简单.和实验测量值的对比结果表明:仿真结果与实测数据吻合较好,用流固耦合方法模拟柴油机活塞组-缸套-冷却水-机体之间的稳态传热是可行的.

Simulation study on the fluid-solid coupled heat transfer of diesel engines

To solve the heat transfer boundary problem among the piston, liner, coolant and body parts, especially the temperature and heat transfer among the coolant, liner and body. A coupled system includes the coupled flow and heat transfer between fluid and solid parts, besides coupled heat transfer among solid parts. As an example, the fluid-solid coupled system of a turbocharged diesel was brought forth. The temperature and flow fields were completed after simulation through FEA software. Comparison between simulation and measurement temperature data shows that simulation results are in good agreement with experimental data and the fluid-solid coupled method can solve the steady heat transfer among piston, liner, coolant and body of diesel engines.