基于RPI模型的内燃机冷却水腔内数值模拟研究

以欧拉两相流模型为基础，建立了适用于内燃机流动传热的RPI(Rensselaer polytechnic institute)过冷沸腾换热模型。并与Robinson的矩形通道试验结果进行了对比分析，验证了模型的适用性和计算精度。将此模型应用于实际内燃机缸盖及冷却水腔内的直接耦合传热计算，同时对单相流和两相流的计算结果进行对比分析。结果表明：沸腾传热可以明显提高冷却水腔的换热效率，并降低鼻梁区等局部高温区域的温度；使用考虑沸腾的两相流模型进行计算模拟时，计算结果与试验结果的误差更小；欧拉两相流计算缸盖火力面测点温度误差相对于纯对流换热模型误差降低了1.78%。

Numerical study of engine water jackets using RPI model

Based on the Euler two-phase flow model, a subcooled boiling heat transfer RPI (Rensselaer polytechnic institute) model of flow and heat transfer for internal combustion engines was established. Compared with the experimental results of Robinson’s rectangular channel, and the applicability and accuracy of the RPI model are verified. The model is applied to the calculation of direct coupled heat transfer in the cylinder head and cooling water jacket of an actual internal combustion engine, and the results of single-phase flow and two-phase flow are compared and analyzed. The results show that boiling heat transfer can obviously improve the heat transfer efficiency of cooling water jacket and reduce the high temperature of local area such as bridge passages, the error between calculation results and experiment results is smaller by using two-phase flow model considering boiling, and the error of measuring point temperature is reduced by 1.78% compared with that calculated by using convection heat transfer model.