Searching for a multispecies solver with buoyant dispersion
Hi,
I want to simulate the injection of helium into air in a garage, at constant temperature. I used the reactingFoam solver adding the gravity effect (rho*g) in the UEqn. The point is that I can't see any buoyancy effects on my results : HE and air are mixing like if there was no difference of density effect between species and I don't understand why... This effect is very important for my simulation because after a while the injection is turned down in order to observe the dispersion of helium. Have I to modify the scalar transport equation? Is an other solver better for my case? I've seen another way using alpha, like in the twoLiquidMixingFoam solver, but I don't know if I can adapt it to my simulation because even if I have two species to transport, I have only one phase. Thank you in advance for your answers ! Pierre 
Hi,
If some of you is interested in my case, I think I found my problem : reactingFoam resolves U equation with a constant density, so doesn't take into account variation of density in the flow due to mixing of species. To solve this problem I am now running twoLiquidMixingFoam solver which calculates changes in density and return it to the velocity equation so that the changes of density impact on the flow. I hope better results with this solver ! 
Thank you for the update Pierre. Are your new results better?

Hi Thekay,
No there not, and I don't understand why... I obtained quite the same results with both solvers. 
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