Calculating Flow Separation Point

[no1schuifan]

Does anyone know of a way to calculate the point at which flow separation occurs?

 

[Andy Resnick]

Tritton (Physical Fluid Dynamics) has a qualitative discussion on chapter 12, and Lamb (Hydrodynamics) has a few sections as well.

The problem is extremely difficult, in the linear case separation ocurrs where the normal component of flow vanishes. This leaves open the problem of calculating the flow.

 

[no1schuifan]

Thanks for your help. The reason i ask is I'm trying to find the critical angle for a diffuser on a car to produce the most downforce so being able to work out past which angle the flow separates from the diffuser is key. Do you think it is worth looking into more or am i aiming for somethign that's just unreasonable?

 

[Andy Resnick]

The good news is that standard airfoil theory should be sufficient for your case- high Reynolds number flow separation has been worked on a lot more than low Reynolds number separation. This may be a good place to start:

http://en.wikipedia.org/wiki/Airfoil