×
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

What are dynamics for sudden water flow stoppage?

What are dynamics for sudden water flow stoppage?

What are dynamics for sudden water flow stoppage?

(OP)
I test swimming pool drains-- sort of.  I block the drain with a foam pad after establishing constant flow gpm. I take data and the pressure/time trace shows an initial sharp drop and then an oscillatory form on top of a decay back towards the pressure of the water head of the tank.  Longer suction pipe lengths have longer periods.  

Does anyone know if this can be modelled as a mass-spring damper system where the mass is the incompressible flow and the spring and damper properties are mainly in the foam?

RE: What are dynamics for sudden water flow stoppage?

The only thing it has to do with the foam is how fast you can put it in front of the drain and block the flow.

If you do that very slowly, you will see that the initial pressure change will be much less than what you are observing now and there will be much less oscillation.

It can be modeled approximately considering the initial velocity of the water in the pipe and the time it takes to stop the flow.

If you are interested in modeling this more accurately, see my web page "blog" - subject Surge / Water hammer

BigInchworm-born in the trenches.
http://virtualpipeline.spaces.msn.com

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