HEAT TRANSFER ANALYSIS OF TURBULENT PARALLEL COUETTE FLOWS USING ANISOTROPIC K-EPSILON MODEL

摘要

An anisotropic k-epsilon turbulence model is employed for numerical analysis of heat transport phenomena in turbulent parallel Couette flow with one surface moving in the flow direction and the other remaining stationary. The turbulent viscosity, turbulent kinetic energy, and normal components of the Reynolds stress are determined. The normal and streamwise turbulent heat fluxes are obtained by means of an anisotropic two-equation model of heat transfer, in which anisotropic eddy diffusivities of heat are expressed in terms of the temperature variance (t(2)) over bar, the dissipation rate of temperature fluctuations epsilon(t), and the velocity gradient. It is disclosed that (1) wall movement causes a reduction in the velocity gradient near the moving wall, resulting in a decrease in turbulent kinetic energy; (2) this attenuation causes a deterioration in heat transfer performance on the moving wall side; and (3) wall movement induces both the velocity dissipation and temperature dissipation timescales with little change of their ratio outside the near-wall region. [References: 13]