Flow Rate & Velocity of Air Through Orifice @ 130 psi

[intuit]

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:

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

 

[LightHero]

.The formula you are looking for is the Bernoulli equation, which relates the flow rate and velocity of a fluid to its pressure and density. This equation can be used to calculate the flow rate and velocity of air through an orifice at a given pressure differential. The equation is as follows: V2 = P1 - P2 + (2*rho*g*h) / (rho * A)Where:V2 = Velocity of Air through the Orifice in ft/sP1 = Initial Pressure in psiP2 = Final Pressure in psi rho = Density of Air in lb/ft3g = Acceleration due to Gravity (32.2 ft/s2) h = Height of the Orifice in ft A = Area of the Orifice in in2Given the information you provided, we can solve for V2 as follows: V2 = 130 + (2*(0.075)*(32.2)*(0)) / (0.075 * A)V2 = 130 + (1.44 * 0) / A V2 = 130 / A If you have the area of the orifice (A), you can plug it in and solve for V2.