说明：  低雷诺k-epsilon 湍流模型方程，流体力学软件COMSOL 3.5的一个例子
(This implemented Low-Re k-epsilon Comsol model is based on the Launder-Sharma damping functions as described in Wilcox s Turbulence modeling for CFD book. Model implementation was in 2D under steady state situation but it can be extended to 3D with relative ease.)