RE: Part full line - water hammer estimation

From: <Steve>
Date: Thu Jun 17 2004 - 07:45:00 EDT

Hi Robin
yeah the fun never stops.
Will look at software but prefer to know how the solution is obtained. I have an irrational fear of becoming an application jockey, that's the reason.
The US military WHAMO (free) was said to be good but it no longer works properly with Windows.
Glad you liked the book. Take Sanks comments about VSDs with a pinch (or a bucket) of salt though.

Cheers

Steve

-----Original Message-----
From: Robin Badcock [mailto:rbadcock@vision.net.au] Sent: Thursday, June 17, 2004 10:52 PM
To: PipingDesign@yahoogroups.com
Subject: Re: [PipingDesign] Part full line - water hammer estimation

Hi Steve,

Still at it I see.

Re your question. There is a fellow countryman of yours that has some evaluation software for precisely what you are looking for, and a demo versions as well I believe. I am not sure as to whether you wish to experiment or not but never the less I have included some details.

Norman Lawgun
Hytran Solutions
Box 51-591
Pakuranga
Auckland, New Zealand
Tel: int+ 649 273 2423
Fax int+ 649 273 2426
email: info@hytran.net
Web: http://www.hytran.net

I have not used the product (nor am I promoting it) but you may wish to have a look for interest sake. On another topic I took your advice and parted with a large wad of Oz dollars (ouch) and purchased Pumping Station Design. This is quite a publication and will be of great use. Thanks.

Cheers,

Robin Badcock

• Original Message ----- From: "Steve McKenzie" <mechproj@xtra.co.nz> To: <PipingDesign@yahoogroups.com> Sent: Thursday, June 17, 2004 8:23 PM Subject: [PipingDesign] Part full line - water hammer estimation

> Gents + 1
>
> I am looking at a water pipeline 2.8km long, flow rate 60l/s, ID
> 227mm. The inlet is atmospheric from a tank. For the first 800m, the
> line drops 150m in elevation. For the remaining 2km, the line is near
> enough to horizontal, discharging into a pond. The friction loss
> under full pipe conditions will be about 30m (dirty). This means that
> the water will drop the first 120m (vertical) the line will run part
> full, with fairly high velocities. At the -120m point the line will
> become full with a fairly sharp head rise due to the sudden velocity
> rise forming a sort of hydraulic jump. I can take a rough stab at the
> part full velocity (using open channel flow theory) and I know the
> full pipe velocity. To get the surge rise, I thought I may be able to
> use Joukowsky's formula; delta H = a delta V /g; a is celerity.
> However, I think the result will be overly conservative,and would
> need to do a fair bit of work before being confident about the result.
> This is a fairly common operating condition, but I do not seem to
> have a clear estimation procedure for this.
>
> Can anyone point me to a book or other reference?
>
> Cheers
>
> Steve
>
>
>
>
>
>
>
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> http://www.pipingoffice.us/ =========================================
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Yahoo! Groups Links Received on Thu Jun 17 07:45:00 2004