RANS解析におけるNACA翼のはく離予測精度の改善

抄録

Two dimensional simulations have been performed for two types of stall conditions about NACA631-012 and NACA633-018. In order to improve the stall prediction, the numerical method that adjust the eddy viscosity of SST k-ω turbulence model based on the adverse pressure gradient and GEKO model developed by “ANSYS” recently were applied. Normally, the eddy viscosity is overestimated at the stall region caused by the adverse pressure gradient, so the eddy viscosity decrease gradually as the amount of the adverse pressure gradient increase in this numerical method based on pressure gradient. On the other hand, in GEKO model, the numerical parameters concerning the flow separation were changed to improve the stall prediction. This adjustment of eddy viscosity and GEKO model carried out the improvement of stall prediction on both NACA airfoils compared to the original turbulence model. These numerical methods can predict stall phenomena with high accuracy without adjusting the numerical parameter for each NACA airfoils.