[Chris_2002]

Hi,

I am simulating a rotor applying a momentum sink to a flow. I've used the Directed Mesh option for the rotor disk and trimmed cells for the fluid. I included a buffer zone, also with a directed mesh, between the rotor and the fluid in an attempt to improve the solution near the boundary between a region with momentum sink term and the rest of the domain without momentum sink term, see image 1.

However, when doing so I get spots along the interface where the streamwise velocity is virtually 0, see second image. Where does this come from and how can I get rid of it?

I've looked into the interpolation between Parts Meshes but a change to higher-order stencils didn't change the result.

It'd be great to hear from anyone who might have a solution to this.

Thanks!

[marmot]

This could be due to the interface not being 100% matched, you can increase the tolerance when creating the interface to improve matching.

When you create an interface you have a parent and child boundary, switch the parent boundary to symmetry than the unmatched surfaces will have a velocity, could be they are wall now.

[Chris_2002]

Hi,

I also got in contact with CD-adapco and it turns out that there was a problem with the interpolation. However, this was not on the simulation/meshing side but rather on the plotting side. I chose the "smooth filled" option for the contour plot which uses an interpolation to smooth the contours. This interpolation can cause spurious effects. When I changed it to "filled" it looked perfectly normal and as expected.

So I think it's safe to say solution found.