Pipe Flow Calculations Forum

you should use D^2 in area formula, and I get 127 m/s with calculator, for Q=0.01 m3/s and D=0.01 m

Well, just checked your results and they are correct.

Now as you expect to have laminar flow with DN65 pipe, it is just what theory says is not possible.

Don't change in second line numerator with denominator - just multiply first row with 1000 and you will get result in mm.

It must be some other application and not one on http://www.pipeflowcalculations.com that I am managing

Absolute

If you can explain in which calculator do you have problem, maybe I can fix it next version.

The web site http://www.pipeflowcalculations.com at this moment doesn't offer any possibility to download any of the available calculators that you have already used. Also selling is not a option at this moment. Instead off selling calculators, I have decided to offer this service free of any charge...

Here is how you can start: Pressure drop in pipe due to friction is: Dp=rho * f * L * V^2 / (2 * D), or (A) Dp = 8 * rho * f *L * Q^2 / (D^5 * pi^2); where is: (B) Dp = rho * g * (H - Dh); - available energy due to level difference if both reservoirs are on atmospheric pressures (Dh - is the change ...

This is non-steady flow problem for which differential equation should be written.
I will try to provide one later today.

The web site http://www.pipeflowcalculations.com at this moment doesn't offer any possibility to download any of the available calculators that you have already used. Also selling is not a option at this moment. Instead off selling calculators, I have decided to offer this service free of any charge...