Ansys Fluent: how the sign of wall shear stress determines the fluid flow direction

Options
Felix98
Felix98 Member Posts: 2
First Comment

Hello, I was confused by the sign of wall shear stress and velocity direction.
Initially, i thought if I want to force the fluid flow in z-direction, i should also set a positive shear stress. However, I found the sign of shear stress and velocity is always oopsite in Ansys Fluent

Tagged:

Answers

  • Felix98
    Felix98 Member Posts: 2
    First Comment
    Options

    When i set a negative z-component shear stress of -1Pa, the z velocity had a positive direction, which indicates a opposite direction.

    [Specified Shear manual:
    In addition to the no-slip wall that is the default for viscous flows, you can model a slip wall by specifying zero or non-zero shear. For non-zero shear, the shear to be specified is the shear at the wall by the fluid. To specify the shear, select the Specified Shear option under Shear Condition (see Figure 7.3.16).]