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-   -   big problem about "there is no reference pressure available" massege (http://www.cfd-online.com/Forums/flow-3d/106323-big-problem-about-there-no-reference-pressure-available-massege.html)

fari August 25, 2012 05:27

big problem about "there is no reference pressure available" massege
 
hi,
dear friends,
please help me give me a guide about the warning.
thanks,
how can I fix the warning? :confused:

dmilano August 27, 2012 14:14

The reference pressure warning means that there is no known pressure defined for all times during the simulation. This is problematic because the solver computes pressure differences, not absolute pressure, which means that the pressure differences may be correct but the absolute pressure may drift. Providing a location where the pressure is known for all times (the reference pressure; usually a pressure BC) gives the solver a location and a value to which it can anchor the pressure differences.

Allowing the pressures to drift is usually only a problem when something depends on the absolute pressure, like an equation of state or a force calculation on a partially modeled object.

vinu2907 March 24, 2013 15:04

Try to specify the reference pressure in the initialization tab in flow 3d (the tab indicates a symbol t=0 in the Geometry & Meshing tab)

For eg: Atmospheric pressure in many cases.


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