Blog

When Pipe Stress Analysis Meets Waterhammer Hydraulics: New Waterhammer Guidelines for Engineers

Jul 11, 2018
1 minute read
Trey Walters, P.E.
Trey Walters, P.E.
Trey Walters is currently Principal, R&D, Engineering Software at Datacor. He previously founded Applied Flow Technology which is now part of Datacor. He has developed simulation software for pipe flow, system optimization, slurries, waterhammer, and pulsation modeling. He has 40 years of experience in thermal/fluid system engineering and has consulted in numerous industries including power, municipal water, oil & gas and chemicals. He holds both a Bachelor and Masters Degree in Mechanical Engineering. He sits on several standards committees of the Hydraulic Institute and is Chairman of their Waterhammer Committee, and he is a Fellow of the ASME.

I am sitting on an airplane at this moment somewhere over the Atlantic Ocean and I am excited. Something that has been in the works for 22 years will happen next Monday, July 16 in Prague, Czech Republic. That is where the ASME PVP 2018 Conference will happen and I get to make a presentation.

Last year I helped AECOM, an AFT customer and AFT Impulse user, develop a set of pragmatic internal design documents for their project on handling radioactive fluid transport. Two of these documents provided their engineers guidance on interpreting and applying transient cavitation predictions. 

We proposed these two documents to the ASME PVP Division and they liked them enough to allow us to publish two new papers at their conference. I will be presenting these papers on behalf of AECOM and AFT.

But why I am so excited about this?

Ever since AFT Impulse 1.0 was released in 1996 (22 years ago), our engineering users have struggled mightily with what to do with the sometimes spurious predictions that result after transient cavitation has occurred. One of the most frequent technical support topics has been on this issue. We have even had customers send their engineers to our office for days at a time and hire us as consultants to help them decipher transient cavitation results so they can finish a design project.

In part as a response to this, we put in significant and sometimes painful effort to implement a second transient cavitation model in 2013-2014 in AFT Impulse 5 ( the Discrete Gas Cavity Model).

So we have now have two cool cavitation models in AFT Impulse. So what?

What AECOM did was go beyond waterhammer. Their experts in pipe stress analysis spent several months collaborating with me and some other AFT staff on waterhammer hydraulics. These two documents combine waterhammer transients and ASME B31.3 piping code. We literally mapped every possible situation that could occur in AFT Impulse to a recommended pipe stress safety factor selection. Yes, really.

The two papers will be presented as Parts 1 and 2 and titled "A Proposed Guideline For Applying Waterhammer Predictions Under Transient Cavitation Conditions Part 1: Pressures" and "Part 2: Imbalanced Forces". If you want to find out more about them,

I am excited because I think our papers can gain traction and start to positively impact engineers who have struggled for many years with this perplexing issue.
Datacor Brand Mark
Media Contact: Jinelle Cioffi
|
(973) 822-1551
|