I wanna simulate an oscillating airfoil problem. The sinusoidal oscillation equation is like : AOA(t)= Mean(AOA)+ amplitude*sinwt. how will I define this oscillating motion in Cfx-Pre?

Thanks Farid

Hi,

Providing the oscillation is a small magnitude then the mesh motion in CFX will handle this quite well.

Glenn Horrocks

Alternatively you could use a time varying inlet U & V velocity components. If you are using a C-Grid with an inlet around the C part of the grid you will need to include a phase shift relating to the location of the inlet boundary nodes. For small amplitude oscillations you can compare/validate your results against Sears/Theodorsen functions.

James

Hi James

Can you please say how can I impose time varying boundary at the inlet in CFX-Pre. I need to impose pressure inlet @ inlet and make it function of time for a duct. I have no idea how do I go about it. Your help will be much appreciated. Thank you

Hello Glenn,

I am trying to define the oscillation of a 2-D airfoil in CFX using the mesh motion feature as you mentioned.

Do you mean using the Specified Displacement option for the airfoil wall boundary condition? If yes, do you have an example of a CEL expression for the X and Y displacement?

Thank you.

Hi,

"Specified Displacement option" - yes, this is the one to use normally. There is an example of using it in the CFX tutorials (tutorial 20).

Glenn Horrocks