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Calculating Air Flow on exit of pipe where inlet is orifice.

Posted: Sat Apr 19, 2014 1:04 pm
by muhayyuddin
Dear All ! Good day.
Pls consider the following case:-
I have a pressure head of 40 bar from where I'm giving an inlet via a small pipe of 10mm dia to a large Pipe of 250mm dia. Inlet of large pipe is made closed with a plate provided only a center bore of 10mm (for passing small pipe through it). While if the valve is fully opened, I take 40 bar as P1 and pressure obtained at exit of large pipe, measured by transducer as P2. Now guide me pls for the following,
1- I'm calculating Air Mass Flow Rate at the exit of large pipe by using "Q = Density x A x v" with density = 1.225, v = sqrt(2x(p1-p2)/density) and A = 3.14/4 x (0.250)sqr. is it OK..?
2- I want to achieve a mass flow rate of 6kg/sec at the end of large pipe. What should be my inlet pressure (P1) for that ?
3- Can i suppose the flow isentropic..? Density can be assumed constant or I should go for compressible fluid flow equations..?

Re: Calculating Air Flow on exit of pipe where inlet is orif

Posted: Sun Apr 20, 2014 12:25 pm
by admin
I think that with orifice calculator you can calculate it easily.
http://www.pipeflowcalculations.com/orifice/