Learning Forum

[Amogh Kulkarni]

Hello, I am new to Ansys Ensight and trying to plot wall shear stress vector LIC in Ensight over a wing(no slip condition). I am following this ensight tutorial video; it doesn't show how to calculate the wall shear stress vector which I need help with. I have tried to play around with the predefined functions (such as BL_CfTau) to create a scalar quantity variable. I am not sure whether the scalar quantity is correct. How can I calculate the WSS vector field to plot surface LIC? Any ideas or recommendations would be of great help.

[CFD_Friend]

Hi Amogh,

The wall shear stress is inherently a scalar quantity because it represents the magnitude of the force per unit area acting parallel to the surface.

 

And  LIC in Ensight only works for vectors. BL_CfTau will return a scalar variable, not a vector.

To plot surface LIC it is better to use a velocity vector as it gives a better representation of flow directions. A surface offset of 0.01 would be suitable.

[Amogh Kulkarni]

Thanks for the answer, then what vector field is displayed as WSS LIC in the tutorial? We can see that in the tutorial a nonzero surface variable is chosen named wall shear stress, it might be a calculated variable. Wanted to know how to go about that.