A research on fluid-solid-heat coupling simulation for diesel engines with considering boiling heat transfer

The strengthening degree of modern engines is higher and higher, so the demand of research on flow and heat transfer processes of up-rated diesel engines is increased more and more. Taking an up-rated 495ZLQ diesel engine as a research object, comprehensive research was made for boiling heat transfer of the coolant, fluid-solid-heat coupling simulation. CFD simulation incorporating the boiling model is an effective approach for such analysis. From the perspective of single-phase flow, boiling heat transfer model based on the method of division description was proposed and developed within CFD framework. The test validation shows that the boiling model could be used in calculating the boiling heat transfer of cooling water jacket. On the basis of that, a 3D fluid-solid-heat coupling model which included engine block, head, liner, gasket and cooling water jacket of 495ZLQ diesel engine was developed by direct coupled method. The fluid-solid heat coupling calculations of the engine were made for cooling water jacket if boiling was taken into account or not. The comparison between the two results show that boiling heat transfer has little effect on the velocity and pressure field, however, the influence of boiling on the heat transfer in water jacket should not be ignored.