Turbulent flow and heat transfer in circular Couette flows in concentric annulus

摘要

A numerical study is performed to investigate heat transfer and fluid flow in the hydro-dynamically and thermally fully-developed region of an annulus, consisting of a heated rotating inner cylinder and a stationary insulated outer cylinder.Emphasis is placed on the effect of rotation of an inner core on the flow structure and the thermal field. A Reynolds stress turbulence model is employed to determine three normal components of the Reynolds stress and its off-diagonal one. The turbulentheat flux is expressed by Boussinesq approximation in which the eddy diffusivity for heat is given as functions of the temperature variance t{sup}-2 and the dissipation rate of temperate fluctuationsε{sub}t. The governing boundary-layer equations arediscretized by means of a control volume finite-difference technique and numerically solved using the marching procedure. An inner core rotation causes an amplification of the three normal components of the Reynolds stress over the whole cross section,resulting in a substantial enhancement in the Nusselt number.