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olih February 5, 2009 10:05

Hi, Although experienced in

Although experienced in CFD, I'm a newbie to OpenFOAM so this is probably a set of very simple questions for someone to answer.

Basically I'm trying to set up a multispecies, buoyant case (i.e. where the gas composition within each cell affects the density - not simply a passive scalar). It's steady, so I've started off with buoyantSimpleFoam but I'm not sure on the best way to edit this for multispecies simulations.

My main difficulty is not the implementation of the transport equations, but how to set up a multispecies simulation and how to get the correct thermodynamic behaviour.

Ideally in my 0 directory I want to have files with the names of the species (O2, N2 etc.)

Many thanks in advance for your help.


gschaider February 5, 2009 11:56

Hi Oli! The closes matches
Hi Oli!

The closes matches to what you want are probably reactingFoam (turn the reactions off if you don't need them) or twoLiquidMixingFoam (if you only got two species, am not sure whether it does temperature)


olih February 5, 2009 12:24

Yes that was my other option -
Yes that was my other option - start with reactingFoam and strip it down, rather than buoyantFoam and building it up.

I take it that reactingFoam has the correct handling of buoyancy that i'm looking for, i.e. density a function of both temperature and composition?


gschaider February 5, 2009 13:27

Hi Oli! It has (correct den
Hi Oli!

It has (correct density), but I'm not sure whether it has gravitation


olih February 6, 2009 16:38

Not having much luck I'm afrai
Not having much luck I'm afraid.

I think I could make progress if I was confident of two things:

1) the correct thermophysical model
2) how to specify the species using speciesTable or similar.

Can anyone help me out on that?



smehdi609 February 9, 2009 13:50

Hi, Your case is like a reac
Your case is like a reacting mixture without any chemical reaction. So, the easiest way is to use reactingFoam and delet the chemical source terms. For thermodynamic model, you can still use hcombustionThermo with a chemkin file. However, just write your speices in file.

abigail March 3, 2009 05:15

Hi, I'm also beginner here.

I'm also beginner here...i'm trying a simple natural convection case with the buoyantSimpleFoam and have few Questions ...

1. in the tutorials, air is being used as model. how can i make use of the other liquids that stated under src/thermophysicalModels/liquids ?

2. for RAS-turbulenceModel what should i do in order to use the SST-Model instead of k-e-Model

can someone plz help me?thanks...

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