抄録
The κ-ε turbulence model is based on the concept of the eddy viscosity model. This model is not-so efficient in flow fields where the Reynolds stresses (-<u_iu_j>^^^-) are significantly anisotropic, such as the fields near air inlets or near outlets, and the fields under the effect of buoyancy. On the other hand, a model which does not use the concept of eddy viscosity, as the differential stress model, does not suffer many problems which is originated by the eddy viscosity model. In the present study, we analyzed two-dimensional isothermal flow fields by utilizing the algebraic stress model (hereafter abbreviated as ASM), a simplified form of differential stress model. Through the comparison of these results with those obtained from the κ-ε model, we then evalulated the validity of the model. In this report, two-dimensional flow field, in which the effect of the streamline curvature is clear, were predicted. ASM captured the effect of the streamline curvature better than the κ-ε model did. Furthermore, ASM evaluated the production term (P_κ) of k more accurately than the κ-ε model did. Therefore, the results of the distribution of streamline, κ and ε in ASM are physically more reasonable than those in the κ-ε model. These results suggest that ASM is effective in analyses of flow fields where the anisotropy of the stresses is significant and eddy viscosity model can hardly be used.
