Calculating Airflow Inside a Pipe

Well I had to consult my fluid dynamics text book from college, because I haven't used this one in a long time (since college for studies!) Henry Darcy, 1858, published this equation for pressure: P2-P1 = (4fLv*v)/d*2*g P2 and P1 are pressures at two different points in a pipe, f is the friction factor which is tricky, according to my text book it can be affected by the medium flowing through the pipe. L is the length of pipe, d is diameter, g is gravity and v is the velocity of the medium.

Also check out the Wikipedia formulas at: http://en.wikipedia.org/wiki/Darcy's_law

thanks a lot for it but ı know just inside a pipe; pressure and pipe size ı dont know anything nıce to meet you by the way ı need short equation or a calculater

Dear Hasan, for understand you can pun on Goggle "Bernoulli formula" may be helpfully for you. Calculate theoretic inside flow is very easy. Many resistances are inside, is big problem. Best regards. Libor Pírko

Look on The www http://vytapeni.tzb-info.cz/t.py?t=16&i=83&h=38&obor=5

If you send me info /datas)I will calcalate

our pressure ınside pipe:8 bar

pipe size:

diameter:5 cm

lenght:5 m

Flow rate in m3/sec can be calculated using the formula Q= AXV where A is Area in m2 and V is the velocity of fluid in m/s. You can measure the velocity using anemometer. Form the velocity and area you get the flow rate.

Hasan,

The equations given are for incompressible fluids (Darcy's Law or the Darcy-Weisbach equation) and do not apply for compressed air. As air is compressible the pressure will compress the air and increase the flow rate, unlike water or other liquids which are incompressible.

Check out this website for a calculator...

http://www.engineeringtoolbox.com/compressed-air-pipe-pressure-d_36.html

Cheers,

Duane

You are correct. I am sorry. I have not noticed the application. I presumed it for air conditioning purpose. Thanks for correcting me.

Dear Hasan Bey,

Check this web addresses, hopefully will help you.

http://www.pipeflowcalculations.com/airflow/theory.htm

http://www.pipeflowcalculations.com/airflow/index.htm

The Wiesbach-Darcy generalised pipe flow equation is applicable.

Try Perry, "The Chemical Engineer's Handbook", any edition.