抄録
A new proposal for closing the energy equation is presented at the two-equation level of turbulence modelling. The eddy diffusivity concept is used in modelling. However, just as the eddy viscosity is determined from solutions of the k- and ε-equations, so the eddy diffusivity for heat is given as functions of temperature variance, <t2>^-, and the dissipation rate of temperature fluctuations, εt, together with k and ε. Thus, the proposed model does not require any questionable assumptions for the "turbulent Prandtl number". Modelled forms of the <t2>^-- and εt-equations are developed to account for the physical effects of molecular Prandtl number and near-wall turbulence. The model is tested by application to a flat plate boundary layer, the thermal entrance region of a pipe, and the turbulent heat transfer in fluids over a wide range of the Prandtl number. Agreement with experiment is generally very satisfactory.
