请问：什么时候用无滑移壁面条件？

雨齐

这两天在模拟超音速流过台阶的问题，壁面设置为‘无滑移壁面’和‘specified shear’差别很大。将壁面设置为无滑移壁面的情况下，沿壁面压力分布在入口附近处会有压力的突升，不知道是不是无滑移边界条件认为壁面处的速度为零，所以静压会很大。
    请教各位大侠：壁面条件什么时候设定为‘无滑移的边界条件’
                          什么时候设定为‘specified shear’
    先谢谢了！！！

雨齐

那位大侠进来帮帮忙啊呵呵

csuperfect

The no-slip condition is the default, and it indicates that the fluid sticks to the wall and moves with the same velocity as the wall, if it is moving. The specified shear and Marangoni stress boundary conditions are useful in modeling situations in which the shear stress (rather than the motion of the fluid) is known. Examples of such situations are applied shear stress, slip wall (zero shear stress), and free surface conditions (zero shear stress or shear stress dependent on surface tension gradient). The specified shear boundary condition allows you to specify the x, y, and z components of the shear stress as constant values or boundary profiles.