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Old   May 1, 2002, 13:50
Default Stag Pressure less than static pressure
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I am modelling a compressible flow model of turbine blade leakage flow. The flow is compressible, transonic and turbulent. I have set stagnation, pressure, symmetry and wall boundaries. The problem is that when the code is run it gives a ratio of stagnation pressure and staic pressure less than 1 at boundary 1(stagnation) message. I am aware that the pressures at the stagnation and pressure boundaries are defined relative to the reference pressure but are they added to the ref. pressure or is that a scaling factor. It seems it is a scaling factor but I am not sure. Similarly for reference temperature is it a scaling factor or is it added to the reference temperature?
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Old   May 3, 2002, 06:40
Default Re: Stag Pressure less than static pressure
john YL
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Reference pressure and temperature are added to the relative values, so they are not scaling factors.

As for stagnation problem you have, the initial condition seems to be important: the static pressure at the boundary is extrapolated from interior, and when the solution is too far away from real solution, this may happen.
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Old   May 6, 2002, 04:10
Default Re: Stag Pressure less than static pressure
Anton Lyaskin
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Concerning the reference temperature - it is used only inside the code and during postpocessing. All the temperatures that you specify at the boundaries must be ABSOLUTE.
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