Influence of Cavitation on the Heat Transfer of High-Speed Mechanical Seal with Textured Side Wall

Abstract

By setting textures on the side walls of a rotor, based on SST k-ω turbulence and the mixture model, the effects of depth-to-diameter ratio, shape, and rotational speed on interface temperature are analyzed. Local Nu number, flow field in textures, and gas distribution are used to verify the conclusion. When rotational speed increases, there are three different stages on the surface: liquid-dominated, mixed two-phase, and gas-dominated. This leads to a big difference in heat transfer on the side wall and causes the temperature on the seal face to increase when cavitation is considered. The distribution of the gas phase is explained through drag reduction, which has a high correlation with the velocity gradient near the surface. For several common shapes, heat transfer enhancement of textures is compared under high speed. The key influencing factor is the depth-to-diameter ratio, which causes flow stratification and reduces heat transfer. Flow stratification leads to different results of maximum temperature on the seal face when cavitation is considered. Results show that at high speed, a deep, circular texture is better when cavitation does not occur, and a shallow triangular texture is recommended when cavitation occurs; a textured side wall can reduce the maximum temperature of the seal face by about 10 °C.