[NeroBlade]

Hi all,

I've been meshing some blocks with 6 solids in the domain (3 cubes, 1 cuboid, floor, ceiling) and been running some CFD and had noticed after computation, the contour results are not smooth transition been sections of the mesh as attached which I also believe is related to the flat iso-surfaces along each refinement region.

The y+ for each region is around 5, turbulence model is k-omega sst so the wall distance is very small. The mesh was generated using Pointwise.

Is there anyway I could resolve this, whilst keeping the mesh y-plus consistent around the solid boundaries?

[RcktMan77]

Yeah, it looks like the scheme you're using in FLUENT is one that advances each cell in time locally at it's own rate (i.e. local time-stepping). Due to the large disparity in cell sizes throughout your mesh, you can see that the solution hasn't reached the same equilibrium state--particularly in areas where you have over-refined the mesh (unnecessarily).

There are three immediate solutions that come to mind: run your solution out much longer, use global time stepping instead such that each cell is advanced in time using a constant time step, or fix your mesh so you don't have such overly-refined regions in the control volume. It's okay to refine the mesh near wall boundaries, but it's really not necessary to allow this to propagate off-body.

Best Regards,


Zach