Buoyancy effect

[zhixchen]

In some very low speed laminar flames, buoyancy could be important. Can we try to make a dfBuoyantFoam from dfBuoyantPimpleFoam?

[SnKzm]

Can the effect of buoyancy be included just through the fvOptions utility that adds gravity force?

[grabtheNS]

hello , i have similar question with @SnKzm . Did you find a solution?In the high pressure the buoyancy great influnce the structures and soot distributuon of the flame. Can I just simply add the rho*g on the velocity equation ？

[SnKzm]

Hello @grabtheNS

Yes, you can add the buoyancy term (rho * g) into the momentum equation to account for the effect of gravity. However, in OpenFOAM, there are sometimes buoyant versions of solvers. For example, buoyantSimpleFoam is a modified version of simpleFoam that includes gravity effects. To my knowledge, the reason for developing buoyant versions instead of simply adding the buoyancy term is that large source terms can introduce significant errors in solvers that use Rhie-Chow interpolation on unstructured meshes. If your computational grid is structured, you can use the source term approach; otherwise, it may be better to use a buoyant version, which isn’t very complicated to implement.

[grabtheNS]

thank you @SnKzm .it was really helpful for me !