NRBC: Sponge layer approach

jinwon park

I am solving 2D compressible flow modeled by Euler equation. In doing, it is necessary to impose the NRBC along boundaries to prevent spurious reflection from boundaries.

Based on the literature, I found that the sponge layer approach is simple to implement and provides relatively clean solution with no wave reflection back to the domain.

The implementation of the layer along four boundary faces was straightforward. However, for four corner areas, that was not as trivial as others. In below figure, we can see the corner area in implementing the sponge layer. If anyone have had such experiences, could you let me know how to define such corners?

Thanks in advance.

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|diff | Sponge layer(easy)

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|easy | Problem domain

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