NBQ and periodic boundaries
Hi,
I'm exploring using CROCO for some stratified flow over topography problems and have some questions. To keep things clear I'll limit this post to one issue.
When testing a simple stratified, nonhydrostatic (NBQ) geostrophic adjustment problem where it is assumed that that d/dy = 0 (flow is invariant in the y-direction, but full dynamics in x-z). The initial condition is a tanh stratification with a localized Gaussian interface displacement. To implement the d/dy=0, I specify NS_PERIODIC and set MMm0=1. However, the code quickly crashes (by developing very large y-velocities) unless MMm0=3. I also find this problem in when rotation is turn off (undef UV_COR), so it doesn't seem to be related to rotation. MMm0=1 with NS periodic conditions works fine in the hydrostatic mode.
Is there a way to simply impose the d/dy=0 invariance with MMm0=1 in the NBQ mode? It is computationally quite inefficient to keep three grid points in y when only one is needed.
-Karl