I was testing a case similar to C064 from the validation of the CSIRO grassland fire. The difference between the validation case file (C064) and my inputs are:
- Horizontal grid size
- Domain height and grid size in the vertical direction (z-direction).
I tried two cases (Input file attached):
Case 1- uniform grid in the z-direction (2 m)
Case 2- grid stretching in z-direction: polynomial stretching with a minimum grid size of 1 m at the bottom and 5 m at the top of the domain.
For some reason, the fire propagates well for Case 1. But for Case 2, the fire does not propagate well. When the grid size at the bottom is fine, there should be no problem with fire propagation. I am not sure where the problem is coming from.
For reference, I am attaching the following files:
- Input file- case 1 & 2
- Temperature contour for cases 1 & 2 at 25 seconds after ignition.
Thank you for your help.