Hi everyone. I wish to know how best to set a TE boundary condition for 2D airfoil calculation, when TE has some thickness. Governing EQ is 2D Navier-Stokes. and geometry is C type. Anyone can help me?

Hi,

It will be good to insert another block behind the TE.

Regards

Li

what does TE represent?

Trailing Edge

If you have a C-grid, you really want a sharp trailing edge, otherwise you are better off with an O-grid. So I would say the quickest way will be to fix your TE, i.e. make the two points defining the blunt edge coincide, which makes it sharp.

I think you are right. It will be the quickest way by using O-grid. Enough grid points can be employed at the trailing edge so that the wake can be captured. However, for this case with a structured grid topology, good quality grid can only be achieved by using multiblock.

Regards

Li

I am not sure about the thickness of this TE, but if it's less than 1% of chord, I would not even bother modeling it. Drag prediction for airfoils, even with a full Navier Stokes solver and the 'right' turbulence model, is a shot in the dark, whereas the TE thickness effect on lift is negligible.

If he uses an O-grid, he will have to throw a lot of points on this TE to make it numerically round. Otherwise he will have non-smooth transformation metrics at the 'kink', which will most likely create numerical problems for the solver. My recommendation: stay with the C-grid and make the edge sharp. For a C-grid, a sharp TE does not pose any problem (metrics are perfectly smooth).

Refer to Jack Moran Computational Fluid Dynamics