Turbulent Taylor-Couette flow and its heat transfer characteristic based on PANS model [基于PANS模型的湍流Taylor-Couette 流及其??特性]

Abstract

The flow field in the annulus of two coaxial cylinders was studied. The turbulent flow simulation method based on partially-averaged Navier-Stokes method (PANS) was established by comparing various turbulent model results with PIV experimental results. The flow field distribution and heat transfer characteristics of slit model were mainly analyzed in turbulent Taylor-Couette flow regime. The influences of Reynolds number, and temperature gradient between inner and outer cylinders on the flow distribution and heat transfer characteristics were investigated. In addition, the formation mechanism of smaller vortices and the distributions of heat flux, velocity and wall shear stress in the slit region were analyzed. The results show that the axial motion of turbulent Taylor-Couette vortices appears aperiodical when the flow regime turns into turbulent Taylor-Couette flow. The axial sizes of Taylor vortices increase with the increase of Reynolds number, and temperature gradient between inner and outer walls. The change of radial velocity and inner wall heat flux along the axial direction shows that the out jet caused by radial velocity has a direct influence on heat exchange between inner and outer walls.When the fluid in the annulus flow goes through the groove area, it impacts on the groove wall surface and forms vortices under the influence of inertia force, viscous force and wall shear force. The velocity in the groove area is consistent with the change of wall shear force, but the change of heat flux is opposite. ? 2019, Editorial Department of Journal of Drainage and Irrigation Machinery Engineering. All right reserved.