Buoyancy effects in gas leakage application

Rotidpor · July 25, 2019, 06:10

Hello everyone.

I would like to model gas leakages.

For the moment, I have used buoyantSimpleFoam and added a passive scalar which is advected by the velocity field and diffused according to its gas/gas diffusion coefficient.
The problem is that for highly volatile and/or heavy/light gases, rho varies according to the magnitude of the scalar and it is not negligible at all...

I have searched through all the posts here and I have yet to find something for my problem.

Is there any solver in openfoam v1812 that is capable of taking into account composition buoyancy effects ? I'm looking for a steady state, incompressible (I mean constant pressure in the rho equation), turbulent, temperature/composition dependant buoyancy solver.

If it does not exist, has anyone ever tried to customize buoyantSimpleFoam to take into account the magnitude of a transported scalar in its rho equation ?

Thank you for reading, have a nice CFD day

Fabrice

The Mad Scientist · July 26, 2019, 14:07

If you just want to incorporate effect of density then you should just reform your phi to be mass flux rather than volume flux.

This will take care of variation in density which is not negligible in your case.

Rotidpor · July 29, 2019, 05:04

I have found that rhoReactingBuoyantFoam can do what I want but it takes way too much computing time since it's a transient solver. I'll look into the code to try to customize buoyantSimpleFoam.

The Mad Scientist · July 29, 2019, 09:20

I would suggest you to go with buoyantPimpleFoam or buoyantBossnesqPimpeFoam.

Also, as you simply want to add some scalar transport equation; you can do so by following the example of addition of scalar transport equation.
This will be much easier and faster.

nikorapk · September 21, 2021, 04:19

is it easy to help me with adding scalar transport equation to buoyantSimpleFoam?

July 25, 2019, 06:10	Buoyancy effects in gas leakage application	#1
Rotidpor New Member Fab Join Date: Apr 2019 Posts: 27 Rep Power: 7	Hello everyone. I would like to model gas leakages. For the moment, I have used buoyantSimpleFoam and added a passive scalar which is advected by the velocity field and diffused according to its gas/gas diffusion coefficient. The problem is that for highly volatile and/or heavy/light gases, rho varies according to the magnitude of the scalar and it is not negligible at all... I have searched through all the posts here and I have yet to find something for my problem. Is there any solver in openfoam v1812 that is capable of taking into account composition buoyancy effects ? I'm looking for a steady state, incompressible (I mean constant pressure in the rho equation), turbulent, temperature/composition dependant buoyancy solver. If it does not exist, has anyone ever tried to customize buoyantSimpleFoam to take into account the magnitude of a transported scalar in its rho equation ? Thank you for reading, have a nice CFD day Fabrice Erf likes this.

September 21, 2021, 04:19	buoyantSimpleFoam	#5
nikorapk New Member Nikolaos Join Date: Oct 2019 Posts: 5 Rep Power: 7	is it easy to help me with adding scalar transport equation to buoyantSimpleFoam?

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
2.5d Multiphase Closed Volume; Problem: Error Stack Overflow; Gas Volume not accurate	namgnirps	CFX	13	November 23, 2018 04:28
Oil and Gas Application (posted on wrong forum)	Consulting	Main CFD Forum	1	November 21, 2007 05:02
Sod shock tube problem with real gas effects	ganesh	Main CFD Forum	0	October 17, 2006 02:22
Two-Phase Buoyant Flow Issue	Miguel Baritto	CFX	4	August 31, 2006 13:02
Gas pressure question	Dan Moskal	Main CFD Forum	0	October 24, 2002 23:02

July 26, 2019, 14:07		#2
The Mad Scientist New Member Join Date: Jun 2017 Posts: 9 Rep Power: 0	If you just want to incorporate effect of density then you should just reform your phi to be mass flux rather than volume flux. This will take care of variation in density which is not negligible in your case.

July 29, 2019, 05:04		#3
Rotidpor New Member Fab Join Date: Apr 2019 Posts: 27 Rep Power: 7	I have found that rhoReactingBuoyantFoam can do what I want but it takes way too much computing time since it's a transient solver. I'll look into the code to try to customize buoyantSimpleFoam.

July 29, 2019, 09:20		#4
The Mad Scientist New Member Join Date: Jun 2017 Posts: 9 Rep Power: 0	I would suggest you to go with buoyantPimpleFoam or buoyantBossnesqPimpeFoam. Also, as you simply want to add some scalar transport equation; you can do so by following the example of addition of scalar transport equation. This will be much easier and faster.