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Old   November 4, 2008, 06:33
Default different pressures in CFX-Post
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sometimes1900
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Hi CFX user, in the compressible flow simulation there are three pressures in the CFX-Post, Absolute Pressure, Pressure and Total pressure. Can anyone tell me what the diffence is? Which pressure is used as the static pressure? thanx in advance Regards
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Old   November 4, 2008, 10:51
Default Re: different pressures in CFX-Post
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John S.
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Pressure = Static Pressure - Reference Pressure Absolute Pressure = Static Pressure + Reference Pressure
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Old   November 4, 2008, 11:39
Default Re: different pressures in CFX-Post
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CycLone
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Total Pressure = Static Pressure + Dynamic Pressure

I.e. it is the Stagnation Pressure
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Old   November 5, 2008, 06:02
Default Re: different pressures in CFX-Post
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Pascal
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Are you sure Cyclone that in CFX-Post Total Pressure= static pressure + dynamic pressure? Isn't it Total Pressure=static pressure+dynamic pressure-Pref?

(I know that your definition is the right one, but I think that CFX-post is internaly changing the definition, 'cause if you plot pressure and total pressure over a wall surface you find the same...)

Let me know if you think I'm wrong, because it's something that I have only noticed by myself...

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Old   November 6, 2008, 12:30
Default Re: different pressures in CFX-Post
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Sorry, you're right. It is reported relative to the domain reference pressure.

At a wall, the velocity is zero, so the dynamic pressure is zero and thus the total pressure is equal to the static pressure.

-CycLone
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Old   February 5, 2013, 12:10
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Hi!
In CFD-Post I can only choose between "pressure" and "total pressure" to be shown on my plane.
I need the "static pressure", so I have to choose "pressure"?

Am I right?
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Old   February 5, 2013, 18:13
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Glenn Horrocks
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Pressure is the static pressure. Note it has the hydrostatic component removed, if that is relevant. See the documentation for more information.
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Old   July 12, 2015, 09:14
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Is it possible to draw dynamic pressure directly in Ansys CFX ?
Because I can draw the figures whic can show the distrubition of the static pressure and total pressure, but I wanna see the distrubition of the dynamic pressure.

If you can explain how it can be possible, I would be very gratefull.
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Old   July 12, 2015, 18:47
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Define a variable with an expression Total Pressure - Pressure. Then it is a variable you can do anything you like with.
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