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-   -   Velocity Jump at InletOutlet (

cliffoi September 8, 2008 05:34

Hi, I originally noticed some
I originally noticed some odd behaviour in a ideal gas flow model I set up and decided to investigate further. I have now set up a very simple 1D pipe model with no-slip walls, an inlet and outlet. The working gas is ideal air. I am noticing an unexpected jump in the velocity in the cells adjacent to the inlet and outlet which seems to be brought on by the viscous drag from the tube walls. The greater I make the viscosity, the greater this jump. I have tried this for numerous of the FOAM solvers and a variety of boundary conditions, fixedValue, fixedMassFluxInlet, etc. and the behaviour presists.
Can anyone maybe explain this behaviour to me. I'd be surprised if nobody has encountered this before.


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