C-grid better than O-grid in Overset for airfoil?
 

Hi,

C-grid is usually better than O-grid during simulation of airfoil's wakes due to the clustering of grids around the wake.

However, is there any advantage when the simulation is done using C + cartesian grid, as compared to O + cartesian grid?

I have already got the code working for the O + cartesian grid and I'm wondering if there's a need to change to C-grid. I need to visualise the wake and hence this is imporant to me.

Currently, there's clustering of pts along the wake for the cartesian grid.

Is there anyone which have experience in this area? Thanks

Re: C-grid better than O-grid in Overset for airfo
 

Using overset you can always put a finer grid in the airfoil wake - just make sure you match grid resolutions in the overlap regions reasonably well and have enough grid points in the area where the wake enters the wake grid to resolve the initial profile. The advantage comes when you consider flows at high angles of attack - the grid cut may not be aligned at all with the direction of the wake travel. Being able to use a secondary wake grid makes it easier to capture the wake without regridding the airfoil. Of course, creating the wake grid has its own set of issues.