combustion, solution problem
 

Does anyone have blinking problem while the problem is solving? I am solving coal combustion problem and it has 1 million nodes size. Once I start parallel running then solver is running and then Out file screen go upward and dowward for a long time at 1st iteration and then move to 2nd iteration. 2nd iteration also shows the same phenomena. One iteration takes about 40 minutes. Please help me!:confused:

I think this is memory problem.

What is your system configuration?Combustion will take more time to solve.

Reduce your mesh size and try again.

Thank you very much for your fast reply. I am using 64gigabite memory. According to windows manager, 10.6GB meories are used. The problem is that CPU. CPU shows only 1% usage and suddenly goes up 90%. I also use SSD and Intel i7-4930K@3.40GHz CPU.1 million cell is not enough for my problem. This is the minimum number to avoid overflow calculation.

Something sounds seriously wrong with your simulation. You probably have a poorly set up physical model. Are you using radiation modelling? A poorly set up radiation model can do that sort of thing.

Coal combustion tutorial radiation setup
 

Thank you very much for your reply. Thermal Radiation: Discrete Transfer, Number of Rays:32, Emissivity: 1, Target Coarsening Rate: 16, some walls emissivity: 0.6 I just followed coal combustion tutorial setup. Is it so sensitive that show such a problem? Could you tell me how to fix this? 24 iterations take 48hours now...I tried number of rays and emmisivity but it didn't help. As far as I know Discrete Transfer model is the only one that can adapt coal combustion problem, isn't it? What kind of radiation solving options which I can chose?

Well, the radiation model is the problem. You may need some serious CPU time on the radiation model - that depends on the detail of what you are modelling.

I recommend you start with a simple model where you have a known answer to reproduce and check the radiation model is behaving as expected. Only once you have a good feel for the radiation model should you attempt the large complex model.

I found some clue.
 

Thank you very much for your help. You are definately right! I put inapropriate options in radiation setup. I look over my model again and change some variables. It works now. :)