Flow rate calculation from pressurised container

[jamesengineer]

Hello

I am currently designing a device to fill gearboxes with hydraulic fluid using air pressure. The idea is to pressurise a container with say 9 litres of fluid inside to cause the fluid to flow out of a hose and into the gearbox.

My question is how can I calculate what pressure will need to be in the reservoir to get a flow rate of 2.5 L/s. Hose ID will be 10mm and approx 2m long.

I have attached a quick sketch of the layout.



"Two hands working can do more than a thousand clasped in prayer"

 

[europipe]

You want to push 9m3 per hour through a hose from a 9L container?
What Viscosity?
Give more and exact data please.

 

[jamesengineer]

Apologies I meant 2.5 litres a minute.

The viscosity will be approx 38.9 cST 40°C.

However the figures are not important as I require the method (equation) in which to find the answer, not the answer itself.

"Two hands working can do more than a thousand clasped in prayer"

 

[Latexman]

"However the figures are not important as I require the method (equation) in which to find the answer, not the answer itself.

Poiseuille's equation for laminar flow (N_Re < 2000).

Good luck,
Latexman

 

[jamesengineer]

Thanks Latexman, looks like that should do it.

However do you know what the metric SI units for this equation are.



"Two hands working can do more than a thousand clasped in prayer"

 

[ione]

http://en.wikipedia.org/wiki/Hagen–Poiseuille_equation

 

[europipe]

http://en.wikipedia.org/wiki/Hagen–Poiseuille_equation

 

[Latexman]

That equation is derived from basic principles, just use consistent units. Maybe, it will simplify (cancel out) to the units you desire for pressure drop.

Good luck,
Latexman

 

[jamesengineer]

Got it. Thanks for the help guys.

"Two hands working can do more than a thousand clasped in prayer"