Effect of Cooling System Design on Engine Oil Temperature

Abstract

High engine oil temperatures have detrimental effect on overall engine performance and durability. High oil temperature is a direct indication of high engine temperature and hence, the inefficient cooling system of the engine. In this paper we show how the systematic investigation of cooling system thought experiments and CFD modeling can reduce the engine oil temperature within the desirable limit. A CFD model was developed for the entire cooling system and results were validated with the experimental measurements. The CFD model and experimental measurement techniques have been described in detail. Separate experimental measurements were conducted for flow and thermal measurements and the corresponding CFD model was validated against these measurements. Various design concepts were investigated and its effects on engine heat transfer coefficients and temperatures, change in system resistances, flow rates and other parameters have been presented. A simple experimental setup was developed for optimization of the centrifugal fan. The optimized fan was then used in the CFD model. It was observed that the reduction in engine oil temperature could be achieved by systematic design changes. However, it comes at the expense of increase in system resistance.