Please give me the equation with a link if possible for determining power for a compressor. I know volume x pressure differential / efficiency but I think the gas being compressed also is a factor. Thank you.
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.
Fred, from your equation a vacuum pump that has a 1bar/.01bar pressure ratio needs more power than a compressor that has a ratio of 10bar/1bar? Is m the molecular weight or the volume?
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.