Compressor Equation

From my old thermo notes, a non-isentropic compressor has a power of:

[tex]\dot{W} = \frac{\dot{m}C_pT_1}{\eta_c} \left[\left(\frac{P_2}{P_1}\right)^{(\frac{\gamma-1}{\gamma})}-1\right][/tex]

You can see the same equation here:
http://www.grc.nasa.gov/WWW/K-12/airplane/compth.html

 

The site seems to be down at the moment but there are online calculators for recips and centrifs at www.processassociates.com

To to process tools section.

 

m is mass flow rate.

I'll have to look around a bit, but a vacuum pump most likely will not be applicable here. I'm not sure, I don't deal with them.

 

Hello, I'm working on a model of a fan and I have the characteristic curves Flow/impelled power and flow/total pressure.

I also have the relation of adiabatic compression you have written but it concerns the Head (in meters) and not the mass flowrate. Therefore, my question is : how do you get the outlet pressure of a fan knowing the characteristic curves and the formula with the head ?

More clearly that possible to convert the Head (m) into a differential pressure (Pout-Pin) or even the outlet Pressure of the fan (Pout) ?

Thank you for any idea.

 

Hi, somebody knows this formula???

HP= Q * 63 * Ln(Pd/Ps)

Is a rare formula that are been used in a pipeline gas.

Thanks.

Felipe

PD: Sorry if I make a mistake in the english, I speak spanish.

 

[tex]\dot{m}[/tex] is the mass flow rate, & is equal to [tex]\rho[/tex][tex]\dot{V}[/tex]

ie. work required also depends upon the inlet density.