Hi,

I am trying to write a pretty simple (in principle) simulation. I have an acoustic point source, and I want to analyze how the resulting pressure evolves as it moves through space.

Currently I have Nx=512, Ny=Nz=64. The point source is at (in grid points) x=15, y=z=32. i.e. it's in the center of the yz plane. I have sensors along the x direction at x=15:497 and y=z=32.

There is no attenuation or heterogeneity in the medium, however I am noticing what seem to be numerical artifacts in the pressure as it propagates, illustrated here: http://imgur.com/a/zBcLM

I notice that if I make Ny and Nz larger (comparable to Nx), then these artifacts are less prominent. However, this doesn't seem to me. I would think that for wave propagation in the x direction, the size of the y and z grids shouldn't matter.

I was just wondering why these artifacts occur, and how they can be mitigated. Am I correct in my assessment that a larger Ny and Nz should work? (at the cost of computation time)

Thank you!