Simulation Research on Cavitation Flow Characteristics of Highly Enhanced Diesel Engine Cooling System

Abstract

This paper establishes a three-dimensional simulation model of diesel engine single-cylinder cooling water jacket. Using the FLUENT calculation fluid software to extract the boundary conditions of the single cylinder water jacket simulation calculation from the calculation results of the water jacket flow field. Considering the effect of the forced vibration of the cylinder liner wall on the cooling water jacket, the wall vibration UDF function of the cooling water jacket is compiled. Using the dynamic grid technology, the two-phase flow mixing model and the cavitation model proposed by Singhal, the three-dimensional unsteady value simulation of the cooling water in cylinder liner was carried out, and the variation of the pressure and gas content of the single cylinder water jacket was analyzed. The results show that the change period of water jacket pressure and gas content rate is consistent with the diesel engine motion cycle. The simulation results can objectively reflect the characteristics of the cooling water flow field, cavitation and its changing law. Comparing the high gas-bearing area with the actual cavitation position, it indicates that the accumulation of a large number of tiny bubbles easily leads to the occurrence of cavitation in the cylinder liner, which confirms the effectiveness of the simulation method.