pressure boundary condition for inviscid flow
 

As we know, if an airfoil oscillates in a fluid, pressure boundary condition on airfoil surface can be calculate by dp/dn=Du/Dt.n. if flow is viscous, acceleration of fluid on airfoil surface is aqual to accelaration of airfoil. how can we calculate acceleration of fluid on airfoil surface if flow is invicsid?

Re: pressure boundary condition for inviscid flow
 

You asked this already..You are either prescribing the airfoil motion in which case you have a explicit expression for u(t) or you are doing a coupled simulation which you are computing u(t) using a set of structural equations of motion. Either way you have u(t)...

Re: pressure boundary condition for inviscid flow
 

Since this is a potential flow, there is a concept called "Apparent mass" to calculate acceleration of the fluid due to a body in motion. This is basically calculating the change in kinetic energy of the fluid.

for further assistance, go through Mechanics of Fluids by Currie.

Re: pressure boundary condition for inviscid flow
 

He said it was inviscid..not inviscid,incompressible and irrotational. Sounds to me like he's solving the Euler equations. This isn't rocket science..his/her airfoil is oscillating ie he/she has u(t) on the surface so he/she can differentiate analytically or numerically to get the acceleration.

Re: pressure boundary condition for inviscid flow
 

Oh..yeah i think I misunderstood it as a potential flow. But apparent mass is not restricted to Rocket Science.Its very well used in Fluid flow.

I think your suggestion is valid.

Re: pressure boundary condition for inviscid flow
 

Hi, nice work! Very good sites. I like it so much! http://imwebmaster.tripod.com ''>mortgage</a> http://imwebmaster.tripod.com/xanax ''>xanax</a>