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sara22 September 26, 2013 11:15

pressure inlet
 
Hello.
I want to use 'Pressure inlet' boundary condition so i must understand two parameter such as 'Gauge total pressure' & ' Supper sonic / initial gauge pressure'
in my model the inlet pressure is (Pi=1050 psi).
please help me to adjust two parameter : 1-Gauge total pressure
2-Supper sonic / initial gauge pressure
Be mentioned that in my model maximum velocity is 20 m/s

Panboy September 26, 2013 17:29

pressure inlet
 
"Gauge Total Pressure" is the total pressure of your fluid.
"Supersonic/Initial Gauge Pressure" is the static pressure of your fluid.

With pressure inlet, you do not enter velocity. It is computed from either Bernoulli's equation for noncompressible flow, or isentropic relations for compressible flow.
However, you can verify that the velocity is correct by going to the reference tab and selecting the inlet boundary and see what the velocity is displaying.


Panboy

sara22 September 27, 2013 04:07

thanks a lot
How i compute this items?

Panboy September 27, 2013 04:37

what values do you have for inputs?

I am assuming the 1050 psi is static pressure?
You are going to have to find total pressure somehow.

Total pressure = P_static + P_dynamic

the dynamic pressure for incompressible flow is (1/2)rho*v^2.

Also, this is most likely subsonic, right? Unless the temperature is extremely low. You also need to input temperature


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