Piping network solution algorithms 3

[dule]

I am familiar with hardy cross method for solving piping networks. Are there any other algorithms?

 

[RWF7437]

There are several variations to the Hardy Cross method. Most allow the iterative solution to converge more quickly.

A good reference for these may be found in:

Analysis of Flow in Pipe Networks by Roland W. Jeppson, Ann Arbor Science.

You may also get some help from the documentation for EPANET; a free program available for solving pipe network problems.

Good Luck

 

[moalarsa]

RWF7437
from where i can get the free programme for network problems
Thanks

 

[RWF7437]

The program is available from the US Environmental Protection Agency (USEPA). I believe their net address is :

http://www.usepa.gov

There is also a support forum located at:

EPANET-USERS@listserv.uoguelph.ca <EPANET-USERS@listserv.uoguelph.ca>

Good luck

 

[moalarsa]

RWF7437
thank you for your support.

 

[moalarsa]

un fortunately both the web address are not correct

 

[RWF7437]

A quick web search found this:

http://www.epa.gov/docs/ORD/NRMRL/wswrd/epanet.html

Russ

 

[llllll]

How can we calculate coefficient of friction in pipes of different material?

 

[llllll]

1.)How pipe sizing is done in steam piping ? And what will happen if pipe size of 150NB is selected in place of 100NB ?

 

[pipinginc]

I'm looking for any data or info for parallel pumping with identically the same centrifugal pumps, can someone answer some of my questions about G.P.M.'s, Hd. Ft. and Velocity, when 2 or more pumps are installed and running?

 

[RWF7437]

To pipinginc:

Many people on this forum can answer your question(s) but you didn't state it clearly. The short answer is that when two pumps act in parallel you add their pump curves horizontally. Then intersect the combined curve with the system head curve to find the operating point. You'll find that you won't get twice the capacity of each pump but something less than that.

Try it and good luck.

 

[dewangga]

There are several numerical method to solve piping networks problems, they are theory linear method, newton-rhapson method, hardy cross method, gradient algorithma method and others.
Basicly, their algorithm are the same. The diffrence is each method use different equation (head equation, flow equation, dQ equation or combination the three of them)

 

[BRIS]

IIIII (Mechanical) You need to post your questions as new threads in order to get sensible answers. As it is I will give you mine:-

It is not possible to calculate the coefficient of friction for different pipe materials. You can calculate it for a specific pipe material and diameter from measurement of flow, temperature and the head loss between two points and then by back calculation.

There is plenty of published data giving roughness measurements for different pipe materials (ks). Also most manufacturers provide estimates of roughness. Roughness is measured as a linear height mm and is typically in the range of 0.03 to 1.0mm. From the roughness the coefficient of friction (f) can be calculated from the Colbrook white equation.(found in any fluid mechanics text book but can only be solved by iteration - ).

From the coefficient of friction (f) the head loss can be calculated from the Darcy equation

h = f . l. v^2/(2.g.d) (again in any text book)

or you can go to

http://home.hccnet.nl/m.dijk/pressure_drop_calculator

and use the free calculator.

 

[fvincent]

For general purposes, you can test the free version of FNESS (flow network evaluator for the steady state) which provides all sort of flow calculations in open and closed loop circuits based on the Finite Element Method. You can find it in

http://www.figener.com.br

fvincent

 

[patrickraj]

IIIIII,

If pipe size of 150NB is selected in place of 100NB,
PRESS DROP will be only 13.17% of original press drop.

 

[CARF]

And last but not least:

http://www.pipeflow.co.uk/

Pipe Flow has a great new &quot;3D interface&quot; which makes it very visual and easy to use.

Good luck,
MVD

 

[olmedo]

Mr.MVD,
I have tried pipeflow 3D but I am not sure if it works on closed loop systems. How?

 

[LHA]

Thanks RWF, I'm going to try it for a stormwater loop, nothing else seems to be working.

Remember: The Chinese ideogram for “crisis” is comprised of the characters for “danger” and “opportunity.”
-Steve