A Two-Equation Heat-Transfer Model Reflecting Second-Moment Closures for Wall and Free Turbulent Flows

A new two-equation heat-transfer model which incorporates some essential features of second-order modeling is proposed. The present model is applicable to heat-transfer problems in both wall and free turbulent flows not unusually deviating from the equilibrium state. Furthermore, by introducing the Kolmogorov velocity scale, the model can appropriately express the low-Reynolds-number effects in the near-wall region, and is also applicable to complex heat-transfer fields with flow separation and reattachment. The proposed model predicts quite successfully heat transfer in both wall and free turbulent flows, i.e., a homogeneous isotropic decaying flow, a homogeneous shear flow, a boundary-layer flow heated from the origin, and a boundary-layer flow subjected to a sudden change in wall thermal conditions, whereas such predictions have been almost impossible with existing two-equation heat-transfer models.