Flow and heat transfer in a rotating heat pipe with a conical condenser

Abstract

The flow and heat transfer phenomena in a rotating heat pipe (RHP) with a conical condenser were numerically studied by using a comprehensive numerical model based on the full discretized Navier-Stokes equations. The impact of parameters such as the heat transfer rate, rotational speed, fluid fill charge ratio and working fluid property on the performance of the RHP were examined. The operation characteristics of the RHP was captured in detail by using the present model. It is shown that as the heat transfer rate increased, the temperature gradient along the RHP experienced an increase. The overall thermal resistance of the RHP was reduced due to the enhancement of natural convection in the liquid at the evaporator section with larger heat transfer rates. The RHP has better performance at higher rotational speed in virtue of the enhancement of natural convection induced by larger centrifugal acceleration. The charge of fluid has impact on the performance of the RHP since the thermal resistance of the evaporator experienced an increase with the increase in the fluid fill charge ratio. As the working fluid, water has a better performance than ethanol, due to a larger thermal conductivity, a larger latent heat, and a bigger thermal expansion coefficient.