Learning Forum

[jcooper]

 

Hi Greg:

I assume that this is a transient run?  If it is, the failure point will coincide with a certain point in the analysis, such as the spray just arriving at the hot plate.  This is the first thing I would try to pin down.  If the dpm particles are not at the plate yet, then the failure may be due to cht numerics. 

 

It looks like the environment is getting up to 5000 K.  This is very odd and may be related to the boundary conditions placed on the cube of air around the plate, or something to do with particles Something is producing this heating. Some questions to ask:

 

 

1. What is the initial temperature of the plate and environment?
2. What is the assumed backflow temperature of the boundaries of the cube of fluid around the plate?
3. What are the droplet temperatures as they move toward the hot plate?
4. What is the Cp property of fluid, particles and plate? (If any of these values are very low, even a little energy will bring things up to really high temperatures quickly.)
5. What is the solid time step?  (This is automated, but often defaults to a very high value that is not always suitable.)
6. As you run, do any of the equations show very high residuals?
7. Are there any turbulence, backflow at outlet or other warnings?

 

I would set up a solution animation that shows a temperature coutour of the particle plume and plate in cross section.  That way you can view the development of the solution in real time and get some clues as to the cause of the high temperatures.

 

Best Regards,

Judy