×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

depth of flow

depth of flow

depth of flow

(OP)
Hi, I am trying to work out the depth of flow in a pipe. I have the velocity, pipe gradient, pipe diameter, and flow entering the pipe. I know the depth of flow must be <0.75 diameter and I just need to put all into a spreedsheet for ease of calculation.

Thanks for the help!

RE: depth of flow

As it appears to be an open channel flow, use manning's equation to calculate the hydraulic radius. With that value and some trial and error procedure, you can work out the water level in the pipe.  You may require two procedures for this trial and error.  One procedure by assuming water is below at the mid point of the pipe cross setion and the other above the mid point cross section.  

RE: depth of flow

(OP)
Hi, I am trying to work out the depth of flow in a pipe. I have the velocity, pipe gradient, pipe diameter, and flow entering the pipe. I know the depth of flow must be <0.75 diameter and I just need to put all into a spreedsheet for ease of calculation.

please note this is a circular pvc pipe part of a network

Thanks for the help!

RE: depth of flow

Jake07 --
You can download from FHWA Visual Urban.  This program will provide you with normal depth in a circular section.  Also you can refer to nomographs of partialy full pipes.  These can be found in hydraulic text books.  Find d/Dfull vs. v/Vfull etc....

Or as chicopee stated crunch out manning's by hand.  Here are eqns. for circular section.

z=D/2-y: z is distance from center of pipe to water surface
         y is depth of flow
x=cos^-1(z/r): x is angle from horz to watersurface
A=D^2/4: A area of flow
P=Dx: Wetted Perimeter
R=A/P:Hydraulic Radius

Q=1.49/n A R^(2/3) S^(1/2): Manning's Eqn.

Good Luck!, I wrote a visual basic routine to compute this.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources