Jump to content

air flow


minicooprc

Recommended Posts

 

what equation(s) would i use to calculate the pipe diameter change?

 

 

[math]\Delta \Phi [/math] = [math]\frac{{2\tan \theta }}{L}[/math]

 

 

Where delta_phi is the pipe diameter change, theta the flare angle of the adapter and L the pneumatic length of the adapter.

 

Is this what you really want or would you like to explain your needs further?

Edited by studiot
Link to comment
Share on other sites

You cannot change the volumetric flow rate (cuft/min) by changing the pipe size or air would accumulate somewhere (or worse appear out of nowhere).

 

The volumetric flow rate Q = Area cross section times the velocity.

 

Note for your units the area is in square feet and the velocity in ft/min.

 

Your second question, what is the diameter change from a 2" pipe to a 3" pipe is surely (3"- 2") = 1"?

 

You cannot calculate the flow within the adapter or about 3 diameters upstream or downstream by these methods.

Link to comment
Share on other sites

 

so the cfm would be the same no matter what size the pipe?

 

 

 

Within limits, yes.

 

If you tried to force the air into too small a pipe, say 1/16", you would probably not be able to do it - the resistance would be too great.

And if you opened out the pipe too far. say 72", it would become a chamber and air would start to circulate as in the atmosphere.

Link to comment
Share on other sites

I haven't checked the arithmetic but your figures are the right sides of the value I got for a 2" pipe.

 

However do you not think your value for the 1.5" pipe is telling you that that flowrate is impractical for such a pipe?

Link to comment
Share on other sites

  • 2 weeks later...

say i have 500 cfm flowing thru 2" pipe and i have an adapter to 3" pipe will that change the cfm or velocity or both and what equation(s) would i use to calculate the pipe diameter change?

I Don't think this will change the velocity of the "air Flow" through the pipe ; but if so please tell me why I am wrong ; and explain how this will work Please and thanks

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.