Validation of reactingFoam for hydrogen dispersion

JakubN · November 13, 2022, 16:15

Hello,

I am trying to validate my code for hydrogen dispersion using reactingFoam, according to validation model from this study (https://www.sciencedirect.com/scienc...18316616#bib34). When I ran the simulation it seems like the hydrogen dont disperse as expected, but rather behave as heavy gas and stays at bottom of the mesh. I tried to change the direction of the gravity, but nothing happened. Also, when I look at my residuals it seems like the solver doesnt compute density as it is always 0 and when I changed the solver from diagonal to PCG it stayed as diagonal at the log file.

I uploaded the directories to https://we.tl/t-OxlPIUnfwx and I would appreciate some help.

Thank you

m.reza · April 24, 2023, 08:45

Quote:

Originally Posted by JakubN

Hello,

I am trying to validate my code for hydrogen dispersion using reactingFoam, according to validation model from this study (https://www.sciencedirect.com/scienc...18316616#bib34). When I ran the simulation it seems like the hydrogen dont disperse as expected, but rather behave as heavy gas and stays at bottom of the mesh. I tried to change the direction of the gravity, but nothing happened. Also, when I look at my residuals it seems like the solver doesnt compute density as it is always 0 and when I changed the solver from diagonal to PCG it stayed as diagonal at the log file.

I uploaded the directories to https://we.tl/t-OxlPIUnfwx and I would appreciate some help.

Thank you

Hi Jakub Naider,
I am simulating cryogenic gas H2 and have the same issue. Could you please help me out?
Thanks

Tobermory · April 28, 2023, 07:56

The answer to Jakub's original question about the rho solver is that the rho equation is very simple - it's an explicit system of equations, and so it does not make sense to solve with anything other than the Diagonal solver. The log file for the Diagonal solver always reports 0 iterations and 0 residual - that's working as intended.

For your question aboput cryogenic H2 and its buoyancy ... check the density predictions and confirm that the cold H2 is indeed buoyant; then check your gravity definition. Visualise the p field and you should be able to tell whether gravity is active and which way it is pointing!

Good luck.

m.reza · May 3, 2023, 01:47

Dear Tobermory,
Thanks for your reply.
I checked all your points. But, I have still the same issue.

m.reza · May 3, 2023, 01:50

I still have the same problem.

m.reza · May 3, 2023, 01:53

Could you please help me out?

November 13, 2022, 16:15	Validation of reactingFoam for hydrogen dispersion	#1
JakubN New Member Jakub Naider Join Date: Oct 2022 Posts: 8 Rep Power: 4	Hello, I am trying to validate my code for hydrogen dispersion using reactingFoam, according to validation model from this study (https://www.sciencedirect.com/scienc...18316616#bib34). When I ran the simulation it seems like the hydrogen dont disperse as expected, but rather behave as heavy gas and stays at bottom of the mesh. I tried to change the direction of the gravity, but nothing happened. Also, when I look at my residuals it seems like the solver doesnt compute density as it is always 0 and when I changed the solver from diagonal to PCG it stayed as diagonal at the log file. I uploaded the directories to https://we.tl/t-OxlPIUnfwx and I would appreciate some help. Thank you suiryagowtham and JCAM like this.

May 3, 2023, 01:50		#5
m.reza Member m.reza Join Date: Apr 2011 Posts: 38 Rep Power: 15	I still have the same problem. Last edited by m.reza; May 4, 2023 at 22:18.

May 3, 2023, 01:53		#6
m.reza Member m.reza Join Date: Apr 2011 Posts: 38 Rep Power: 15	Could you please help me out? Last edited by m.reza; May 4, 2023 at 22:15.

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April 28, 2023, 07:56		#3
Tobermory Senior Member Join Date: Apr 2020 Location: UK Posts: 736 Rep Power: 14	The answer to Jakub's original question about the rho solver is that the rho equation is very simple - it's an explicit system of equations, and so it does not make sense to solve with anything other than the Diagonal solver. The log file for the Diagonal solver always reports 0 iterations and 0 residual - that's working as intended. For your question aboput cryogenic H2 and its buoyancy ... check the density predictions and confirm that the cold H2 is indeed buoyant; then check your gravity definition. Visualise the p field and you should be able to tell whether gravity is active and which way it is pointing! Good luck.

May 3, 2023, 01:47		#4
m.reza Member m.reza Join Date: Apr 2011 Posts: 38 Rep Power: 15	Dear Tobermory, Thanks for your reply. I checked all your points. But, I have still the same issue.