Adding buoyancy to
 

Hi,


I am trying to simulate a human cough. The basic description of the requirements that I have is for a jet laden with particles. The incoming air into the domain should be hotter than the ambient air and so there should be a buoyancy effect. The laden particles should be Lagrangian, taken to be water droplets, and they can undergo a phase change.


Now, I was hoping for assistance in choosing a good way to go about this.


My first thought was to use reactingParcelFoam, however, the issue I am having with this solver, is that I am scratching my head on how to add buoyancy of the hot incoming air. I have thought about adding buoyancy into the fvOptions file, but given that my average density, will be say ~1.1 in the domain, and the hotter air should decrease in density and thus rise, but the problem I have here is that it seems to add a source term to every part of the domain and so the whole field gets a velocity in the direction of gravity.


Any suggestions or an appropriate solver suggestion would be much appreciated.


Kind regards.

There is a buoyant version of reactingParcelFoam(i.e., buoyantReactingParcelFoam) -- at least in the latest release (Openfoam-8) -- that is separate from the base solver. In older versions it appears that buoyancy was incorporated directly in the solver... you would just need to make the gravity vector nonzero. The hotBoxes tutorial (https://github.com/OpenFOAM/OpenFOAM...eFoam/hotBoxes) should be a good reference.

Caelan