Target Coarsening Rate for Discrete Transfer Radiation Model
 

Hello to all dear forum users,

My problem includes a gas filled annulus where inner hotter cylinder radiates to an outer cylinder. I am simulating this with surface to surface discrete transfer radiation model. The problem is I can't control the coarsening rate at Solver Control tab, it simply doesn't exist. And when I check the output file It is like this:

Target coarsening rate = 124560
Number of fine grid elements = 124560
Number of radiation elements = 1
Actual coarsening rate = 124560

This scares me since I am reading that default coarsening rate is 64 (or 16 I am not sure). And I am not sure if I am simulating the problem correctly.

I have read from an old post that for some situations this parameter cannot be specified, but at there these situations were not clarified.

It would be really helpful If someone can clarify the situation.