Pipe Depth of Flow 1

[tcarcamo]

Does anyone know how to created a formula for depth of flow in a circular pipe in excel? I am trying to create this formual in autocad with expressions. Any help will be greatly appreciated.

Tony
Senior Design Tech

 

[DamEng1]

Not sure what you are asking? Depth of flow at a given Q, like with Mannings Eq. or what?

 

[tcarcamo]

yes at a given Q like mannings equation. What i have is the velocity, friciton slope, slope, size of pipe,n, and capacity worked out but i cant figure out how to write a formula for depth of flow in a pipe in excel. If i can write the formula in excel i'm pretty sure i can do it with an autocad expression for a pipe label.

 

[coloeng]

I have an Excel spreadsheet that provides flow dependent on depth. If that is what you want, it is attached.

 

[WL123]

You can also look at this thread from last year. I posted a spreadsheet that calcs the flow depth and velocity for any flow. The macro is in Visual Basic and runs in the excel spreadsheet. Instructions are in the tread.

http://www.eng-tips.com/viewthread.cfm?qid=227242

 

[WL123]

Wish I knew how to edit my comment above, The macro might be a little confusing, it basically iterates through Manning's equation to solve for the depth of flow. The Macro can be reduced in size, I just jammed it together to get it to work fast.

 

[Crystalct1]

You can easily use goal seek in excel. No macro needed, but my way would be a one-by-one calculation - not a batch calculation for a long list of pipe.

Basically, you are putting manning's equation in one cell, with references to other cells for n, R, and S. You'll need R as a function of depth in order for this to give you depth. So you would be using your area and wetted perimeter in terms of d.

Draw a picture of the cross-section of pipe to help with the equations. Let me know if you need more help. I have done this myself.

 

[oregonpe]

Try the UD-Culvert v2.00 spreadsheet from this site:

http://www.udfcd.org/downloads/down_software.htm

the pipe section will do the job. There are many other very useful utilities on this web site.