Learning Forum

[Shiv1510]

Hi everyone,

I am trying to perform simulation on an undulating aero-foil in Ansys fluent.I understand there is an amazing in-build option to calculate drag on the surface of the aero-foil and plot/save it in time. However, I want to find decomposition of the same drag force into its pressure and viscous components and save it in time. 

I know the report forces option does this very well, but I could only figure out that it works for one particular/last time step/steady state. How can I make it work for transient cases and save the pressure and viscous components of drag separately ?

Can anyone help me please ?

[DrAmine]

For pressure force this is straightforward as you have the pressure variable and the facet area. From it you can abstract the viscous component.

[Shiv1510]

Hi Amine

Thank you for replying,

Do I have to define a custom field function for pressure* area ? and apply it as an integral or sum on the surface of the aero-foil ? How would I choose the direction vector for the force ?

Best regards

Shiv1510

[DrAmine]

You need to use the Are Vector to get a force vector (not only area magnitude).

[Shiv1510]

Do you mean the the X-Face are under mesh options in custom field definition ? (e.g: p*x-face area)

[DrAmine]

Yes and sum.

[DrAmine]

also check the exact definition of the force in Fluent as there is use of reference pressure too (check if that value is set in your case)

[Shiv1510]

Great ! Thanks it worked.