Air flow distance from nozzle 1

[olssonloket]

Hello!

I need your help with this...
Through a nozzle with diameter 5 mm, there is an air flow. The mass flow is 0.01 kg/s, and the flow is horizontal. The air flows into air with atmospheric pressure. How far will the air flow reach before the velocity is zero? Or even better, is it possible to calculate how the velocity varies with the distance from the nozzle? I know its hard to calculate an exact value, but an estimation would do. Seemed so easy, but can't figure it out...

 

[JStephen]

The problem isn't as simple as it sounds. Two or three different approaches occupy several pages in the ol' Boundary Layer Methods textbook from college.

Theoretically, the velocity won't ever reach zero.

 

[olssonloket]

No, I've found that it's not easy...
But isn't there a way to estimate at what distance from the nozzle the speed has decreased to a certain speed? I only need a rough estimation...

 

[hacksaw]

sure, but you must narrow the scope of your problem by imposing various restrictions on the expansion process and the flow path. you can make any assumptions you like...

 

[olssonloket]

I hoped for some more helpful answers, but now I've found a way around the problem that made it a lot easier so never mind... Great forum though!

 

[maric]

Hi, olssonloket,
I have exactly the same problem, trying to eximate roughly the velocity distribution outside a cylindrical nozzle. You told you found a way around. Would you mind telling me your approach? thanks a lot