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Old   May 21, 2011, 09:32
Default Totalpressure Ansys
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Niklas
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Hello,

i have a problem with the Totalpressure in Ansys-CFX Post. Ive drawn a Line in the center of my domain and extracted density, velocity and static pressure along this line. I imported the data in excel and calculated the Totapressure by:

p_total=p_static + (Density/2)*(Velocity^2) from my fluid mechanics script

The problem is, the calculated totalpressure is very far away from the totalpressure extracted from Ansys along the line. What is my mistake? Do i have to calculate the Totalpressure another way because of compression effects?

regards
Niklas
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Old   April 9, 2013, 05:57
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you should use isentropic relations if your case is compressible.
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Old   April 9, 2013, 19:56
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Also keep in mind that the density, pressure and velocity variables are interpolated in your exported file, but when you use the total pressure variable in CFX it is calculated directly on the control volumes. This means your calculation will have interpolation errors in it. The CFX reported total pressure is more accurate.
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