May the Force Be With You: Evaluating Unbalanced Forces Caused by Waterhammer
A common task among pipe stress engineers is to evaluate loads on pipe systems caused by waterhammer. Since AFT Impulse 4.0 was released our users have had the ability to calculate waterhammer-induced unbalanced forces for use in any pipe stress analysis application. In addition, our users can create specially formatted transfer files for direct use in CAESAR II and TRIFLEX.
However, the process of calculating such forces in AFT Impulse and then applying them in pipe stress software is not as straightforward as it sounds. Our customers have asked for assistance in this process. I have teamed with Jim Wilcox of CodeCAD - AFT's distributor in Canada - to write a white paper on how to generate forces in AFT Impulse and apply them in CAESAR II. Jim's many years of experience with CAESAR II as well as his familarity with AFT Impulse as a distributor was a key factor in us being able to create this unique document.
Here is a link to where you can download the white paper: Evaluating Dynamic Loads in Piping Systems Caused by Waterhammer.
As a point of interest, this effort began as a conference presentation at Intergraph's CADWorx and Analysis University in 2009. We were invited back again in 2011 and presented a paper entitled "Transient Hydraulic Analysis for CAESAR II Evaluation". After the 2009 presentation we began work on a white paper and it took us a few years to refine the example and the content.
This version of the white paper is in U.S. customary units and we are currently at work on a metric version.
We expect this white paper to offer significant help to those performing this important engineering task. Please tell us what you think!