Calculation of average Velocity cm/s

[GCentric]

Hi

I'm trying to calculate the Average Velocity of a gas... So far I've managed to work out the outlet flow based on the Poiseuille equation, an example of which can be found here:

http://www.sge.com/uploads/8e/ab/8eab97 ... 0025-C.pdf

I've got this to work without problem but have not managed to get the correct values for the average velocity cm/s

Does anyone have a formula to share with me?

Thanks

P.S.

I'm actually after the 'inlet flow' shown in some software calculators (Agilent Column/Pressure flow calculator for example). I can get the outlet flow based on the Poiseuille formula. Does anyone know where the 'inlet flow' value comes from?

[Consumer Products Guy]

I've always had success using Agilent's flow calcualtor software, don't fully understand why that cannot deliver what you request. we get cm/sec linear velocity using that.

[GCentric]

Hello

I've also got the Agilent software but I'm busy creating an application that needs to do the calculations.

Thanks

Edit:

Velocity = FlowRate/Area;
Velocity = FlowRate/(pi * radius2)

Gets close. I need to add in temperature?