×
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

EPANET Total Head of Junction

EPANET Total Head of Junction

EPANET Total Head of Junction

(OP)
Considering Bernoulli's Equation, the Total Head should be the sum of the Elevation/Velocity/Pressure Heads at each point. My EPANET question is this: Is Velocity Head included in the computation of "Total Head" at a given Node? If so, which velocity is used? One of the upstream velocities? A downstream velocity? Average of those? Also, if it doesn't include velocity head, why not?

I've attached an example screen shot, and running a quick calculation shows that 4552+77.88*2.31 ≈ 4731.9 which is very close to 4731.73 ft of total head, so I'm imagining that maybe the Total Head doesn't include velocity head...

Hopefully I'm asking this in the right place. If not, I apologize and please delete.

Thank You!!

RE: EPANET Total Head of Junction

Velocity head is not usually included. It is usually fairly insignificant in a typical distribution system.

RE: EPANET Total Head of Junction

(OP)
Gocha, thanks for the reply coloeng! I guess looking at, say, a V = 10 ft/s would yield a velocity head of only (10^2)/(2*32.2) ≈ 1.55 ft => 3.59 psi, which isn't a ton of pressure I suppose... And perhaps by not including it, we would have conservative results. Thoughts anyone?

RE: EPANET Total Head of Junction

10 ft/s actually only gets you 0.67 psi. Also, 10 ft/s is awfully high for a typical distribution system.

RE: EPANET Total Head of Junction

to convert feet of head to pressure in psi, you need to divide by 2.31 not multiply. that will solve a lot of your issues

RE: EPANET Total Head of Junction

(OP)
cvg, that's correct. PSI = Feet of Head divided by 2.31,

however, in my case, I'm converting in the other direction. 77.88 PSI, when converted, is 179.9 feet of head.

This makes my equation: 4552 ft + 179.9 ft = 4731.9 ft

Units can definitely be a bugger sometimes though. I mix them up more often than I'd like to admit!

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

White Paper – Your Construction ERP RFP Checklist
Selecting business software for a medium to enterprise-sized construction concern is extremely challenging in large part because most enterprise resource planning (ERP) suites originated in the world of repetitive manufacturing and are therefore a poor fit for a project and asset-centric business. However, midsize to large contractors need the predictable, auditable processes that ERP delivers. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close