Convective heat transfer under different jet impingement conditions - optimum design to spray parameters

Purpose - This paper aims to improve the cooling performance of the impinging jet to the machining and power transmissions, and provides more parameters to the design of the cooling system. Design/methodology/approach - A multiphase flow model with heat transfer terms is established to calculate the convective heat transfer coefficient. The computational fluid dynamics method is used to simulate the jet flow. The convective heat transfer coefficients with different spray parameters are calculated and their variations are obtained. Temperatures are tested to reflect the cooling performance (convective heat transfer coefficients) with different spray parameters. Findings - The results show that the higher convective heat transfer coefficient can be obtained with the same flow rate by decreasing nozzle diameter while increasing either the number of nozzles or the oil supply pressure. The spray distance was found to have little influence on convective heat transfer; however, the more the spray is directed parallel to the surface, the higher the convective heat transfer coefficient. The computational results coincide well with the experimental results. Originality/value - The research presented here leads to a design reference guideline that could be used in machining and power transmissions to reduce the temperature, thus improving their quality and efficiency, and preventing failure at high speeds and/or under heavy loads.