Re: 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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Received on Thu Jun 17 06:52:00 2004