How can we apply pressure boundary condition on airfoil surface oscillating in an inviscid fluid flow?

Why do you need a pressure boundary condition, not the standard vanishing normal velocity on the airfoil?

I want to solve unsteady Euler equations using C-type mesh. that's why I need pressure boundary condition on the airfoil surface.

the pressure BC can be obtained from the expression(latex math): {\partial p \over \partial n}=-\rho \vec{a}_b \cdot \vec{n} where \vec{a}_b is the acceleration of the body and \vec{n} is a vector normal to the surface.

the equation you mentioned must be applied in the fluid and we know that fluid particles slip on the airfoil surface and for slip condition we know that acceleration of body is not equal to fluid particles !

http://aiac.ae.metu.edu.tr/db/serv.p...=AIAC-2007-017

this might help you...

You apply this to get the pressure and then a condition on the normal velocity(ie that they are the same for the fluid and structure). Look at any papers which deal with fluid-structure interaction and the Euler equations.