Chromatography Forum

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?

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.

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?