I have been searching for formulas to determine the flow rate and velocity of air through an orifice at a given pressure differential. I need to know the flow rate to determine the CFM requirements of the compressor. And I need to determine the velocity to be able to accurately size the orifice for the job intended. I have found different formulas. Some more elegant than others. I need simple formulas to get a usable numbers. The application can be fine tuned by trial and error. The variables used should be as follows:(adsbygoogle = window.adsbygoogle || []).push({});

V = Velocity in feet/sec

C = Orifice Coefficient = .95

P = Pressure differential = 130psi (150psi being released into 30psi)

A = Orifice area in inches squared = The orifice sizes will be in the range of .055" to .157" Diameter.

T = Air temperature = 70 degrees F.

I don't need an elegant formula, but if other variables are needed, use:

W = Mass of Air = Assuming .075 lbs/ft

Atmospheric Pressure will not be a factor in this application

**Physics Forums - The Fusion of Science and Community**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# I need two simple formulas to figure flow rate and velocity of air through an orifice

Loading...

Similar Threads - need simple formulas | Date |
---|---|

Energy needed to deform metal sheets | Jan 30, 2018 |

I need help on my rocket engine thrust equation | Nov 25, 2017 |

Turbojet -- I need help with an explanation about how a turbojet works | Nov 14, 2017 |

Need a simple accelerometer for a demo kit | Jan 13, 2016 |

**Physics Forums - The Fusion of Science and Community**