Applicability of k-epsilon turbulence model for heated flow

In order to perform the detailed analysis of the heat-transferring flow for the fuel channels in a VHTR core, the applicability of k-epsilon type two equation turbulence model which recently has become the main of numerical analysis to heated flow was examined. In this study, the three models of Jones-Launder, Hoffman and Chien were applied to the turbulent flow in a circular pipe, and as the results, it was found that the almost satisfactory results were obtained in the case of isothermal flow, but in the heated flow with the intense change of physical property values, all the models failed to properly reproduce the experimental results, and it is necessary to further improve the turbulence models. This code is intended for the analysis of the heat-transferring flow of heated gas, of which the change of property values is intense, but the turbulence model itself is general, and can be applied to other fluids. The calculation system is made supposing a circular pipe, a torus and parallel plates. The code comprises one calculation control part and four subroutines, that is, for the velocity, turbulence energy k, turbulence dispersion epsilon and passive transport quantity. The analysis model, the turbulence model, the procedure of calculation, and the application to the gas flow in a circular pipe are reported. (Kako, I.)