Mixed convection heat transfer to an upward turbulent flow of supercritical water in a pipe

Abstract

In a turbulent supercritical fluid flow, the variations of the fluid properties are significant near the pseudocritical temperature. Such dramatic variation of the fluid properties makes the convection heat transfer to a supercritical fluid a complex phenomenon. A number of studies in recent years have used the available CFD codes to predict heat transfer coefficients. In this study, the upward turbulent flow of supercritical water in a pipe has been examined by means of the FLUENT software. To model the turbulence, RSM and RNG k-ε models are employed. The results associated with RSM model demonstrate a better agreement with experiments. The basic characteristics of convection heat transfer in a supercritical fluid medium, including the effects of pressure and heat flux for example, are predicted satisfactorily. However, the inadequacy of existing turbulence modeling seems to be apparent.