Different Printed Diffusion Numbers in OF 7 and 4.x ChtMultiRegionFoam

SamZar · March 9, 2020, 14:39

Hello everyone,

I am modelling a cylindrical specimen under a time-variant heat flux. The specimen is placed under the heater and the surrounding is air.
I used frozen flow assumption for air for now as the radiation is high, and there is no convection. Everything is set to be laminar.

I run my case using ChtMultiRegionFoam in OpenFoam 4.1, 4.x and 7. As I checked the log files for the solver, I realized the calculated values are different for diffusion number significantly for OF 4 and 7. And the temperatures on specified probes are different as well.
As far as I know, the definition of diffusion number is not something that can change in equations.

I was wondering if anyone here is familiar with this issue and can help me to understand what is going on in the codes/equations and how I can solve this issue.

Please let me know if you have any question or need more description.
Many thanks,
Sam

SamZar · March 11, 2020, 10:05

Hi,

I was wondering if anyone have had such an experience for the issue I explained.

Thanks.

March 9, 2020, 14:39	Different Printed Diffusion Numbers in OF 7 and 4.x ChtMultiRegionFoam	#1
SamZar New Member Join Date: May 2019 Posts: 4 Rep Power: 6	Hello everyone, I am modelling a cylindrical specimen under a time-variant heat flux. The specimen is placed under the heater and the surrounding is air. I used frozen flow assumption for air for now as the radiation is high, and there is no convection. Everything is set to be laminar. I run my case using ChtMultiRegionFoam in OpenFoam 4.1, 4.x and 7. As I checked the log files for the solver, I realized the calculated values are different for diffusion number significantly for OF 4 and 7. And the temperatures on specified probes are different as well. As far as I know, the definition of diffusion number is not something that can change in equations. I was wondering if anyone here is familiar with this issue and can help me to understand what is going on in the codes/equations and how I can solve this issue. Please let me know if you have any question or need more description. Many thanks, Sam

March 11, 2020, 10:05		#2
SamZar New Member Join Date: May 2019 Posts: 4 Rep Power: 6	Hi, I was wondering if anyone have had such an experience for the issue I explained. Thanks.