How Bosfluids calculates unbalance forces

[laura80]

Hello

Id like to Know what formula aplies Bosfluids to calculate unbalance force produce by water hammer in straight section of the pipe system.

I know the sofware is based in characteristic method to find the the velocity of the wave of presure produced by water hammer, but I want to know the formula used to calculate the unbalance force, and if friction factor of the pipe is considered in this formula.

Thank you in advanced.

 

[BigInch]

There is only one way to do it that I know of. Pressure x cross_sectional_area at point 1 - Pressure x cross_sectional_area at point 2. Obviously pressures at any point should be calculated considering frictional losses from flow in the pipe. Pressure at one of the points should be the maximum in the segment and pressure at the other point should be the minimum in the segment in order to determine the maximum force acting on the segment. If the orientation angles of pipe axes at each point are different, the appropriate sine and cosines should be used to balance the sum of forces in each direction.

But I do not know for a fact that Bos follows that or any other specific method. If you can run a test case, please let us know if you observe similar results to those predicted above.

Let your acquaintances be many, but your advisors one in a thousand’ ... Book of Ecclesiasticus

 

[vpl]

Assuming that Bosfluids is a computer program -- the only ways to find out what formula they use would be (1) look in the user's manual or (2) ask them.

Patricia Lougheed

******

Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of the Eng-Tips Forums.

 

[laura80]

Thank you very much BigInch for your answer. In the manual I didn't see anything about it. I will run a test job and try to check when i have a litle more time at work.

Thank you very much.

 

[BigInch]

Start with a straight piece of pipe.
After you figure out the math behind that, add a 90deg bend to the next test case.

Let your acquaintances be many, but your advisors one in a thousand’ ... Book of Ecclesiasticus

 

[LSThill]

laura80 (Mechanical)

Please Contact support at

Petra Wiesnekker
Office Assistant
Dynaflow Research Group bv
Houtsingel 95
2719 EB, Zoetermeer
T. +31 79 361 5150
F. +31 79 361 5149
kvk nr. 27320315

http://www.dynaflow.com

L S THILL