[DanM]

Hello everyone,

I have a fairly general question: When solving a flow problem with an unsteady velocity inlet, how should the pressure boundary condition at the inlet be defined? For steady flow a zero gradient condition is adequate and ensures consistency at the inlet boundary. However, for an unsteady velocity boundary I believe the pressure should also fluctuate in time and space. Zero gradient is still often used for the unsteady case, but doesn't that introduce an error?

I would appreciate your comments!

Thanks a lot,

Dan