応力フラットネス・パラメータの輸送方程式を考慮した非線形κ-ε-A三方程式乱流モデルの開発  [in Japanese] Development of a Nonlinear Three Equation Eddy Viscosity Model Coupled with Transport Effects of a Stress Flatness Parameter  [in Japanese]

This paper describes a development of a new nonlinear three equation eddy viscosity model for capturing two component turbulence that appears in flows near walls and free surfaces. In a nonlinear κ-ε eddy viscosity model, dependence of Lumley's stress flatness parameter : A, has been included by solving its transport equation as the third variable. The proposed nonlinear κ-ε-A three equation turbulence model has been tested in fully developed plane channel, open channel and plane Couette-Poiseuille flows as well as several homogeneous strain fields. The results have shown its very encouraging performance in capturing anisotropic turbulence near both wall and shear free boundaries without any recourse to topographical parameters.