Calculation of turbulent fluid flow and heat transfer in ducts by a full Reynolds stress model

A computational method has been developed to predict the turbulent Reynolds stresses and turbulent heat fluxes in ducts by different turbulence models. The turbulent Reynolds stresses and other turbulent flow quantities are predicted with a full Reynolds stress model (RSM). The turbulent heat fluxes are modelled by a SED concept, the GGDH and the WET methods. Two wall functions are used, one for the velocity field and one for the temperature field. All the models are implemented for an arbitrary three-dimensional channel. Fully developed condition is achieved by imposing cyclic boundary conditions in the main flow direction. The numerical approach is based on the finite volume technique with a non-staggered grid arrangement. The pressure-velocity coupling is handled by using the SIMPLEC-algorithm. The convective terms are treated by the van Leer scheme while the diffusive terms are handled by the central-difference scheme. The hybrid scheme is used for solving the equation. The secondary flow generation using the RSM model is compared with a non-linear k- model (non-linear eddy viscosity model). The overall comparison between the models is presented in terms of the friction factor and Nusselt number.
Keyword: Reynolds stress model, duct flow , non-linear k- model , turbulent flow