4 Replies Latest reply on Oct 7, 2015 4:58 PM by Fausto Bartra

# How do you set the inlet pressure for flowsimulation?

any detailed information of how to set the inlet pressure?

thank you

Fausto Bartra

• ###### Re: How do you set the inlet pressure for flowsimulation?

When you set up your boundary conditions, you can choose pressure as one of the options in the sidebar menu. You can choose static or total pressure, and you can set thermodynamic properties as well.

• ###### Re: How do you set the inlet pressure for flowsimulation?

Amit:

thank you

I tried that, but the velocity keeps increasing to very high numbers

I am just trying to run the flowsimulation "Muffler" example

Here are my settings:

Boundary conditions:

1. Inlet = static pressure = 15psi
2. all other six outlets = static pressure = ambient 14.6PSI
3. Added a real wall (the inside of the muffles) Rough = 0.1u inch

so far velocity is reading 2615 in/s for the above settings

any suggestion will be apreciated

Thank you again

Fausto

• ###### Re: How do you set the inlet pressure for flowsimulation?

That doesn't seem odd to me. Imagine a simpler scenario, where pressurized air in a pipe is escaping into the atmosphere. The pressure inside the pipe is 0.4 psi higher than the atmospheric pressure (as in your case) and we'll consider the air in the pipe to be stagnant for the sake of simplicity. If we apply Bernoulli's principle we get a simple equation for the velocity of the escaping air:

V = square root ( 2 * [pressure difference] / [air density])

Plugging in our values we get a velocity of 67.5 m/s, which is equivalent to 2660 in/s. So we're very close to what you're seeing.

• ###### Re: How do you set the inlet pressure for flowsimulation?

Amit:

got it

Thank you

Fausto