Help needed with overset/chimera

Ben

Hi,

I'm now trying to modify my code to allow overlapping grid ie overset/chimera capabilities.

I'm using fractional step FVM structured grid. I tried to simulate a 2d cylinder using o-grid overlapping with cartesian grid in external flow.

Using coarse grid, I managed to get a visually correct plot. Moving the o-grid at any position did not affect the solution.

When I used a refined grid, the solution blows up. On inspection, the problem happens at the interface. The velocity interpolated are in the wrong direction. Btw, I'm using bilinear interpolation.

I'm quite inexperienced with overset grid. Can someone recommend what I should do next to correct the problem?

thanks