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Trey Walters

Waterhammer: In our Booth?

What booth and why does it have waterhammer? Come find out! In a few weeks, AFT and yours truly will be at the Turbomachinery and Pump Symposia (TPS) in Houston – September 10-12 to be precise. We will have a booth (#2824 for those who are coming). And we will have waterhammer. Not just waterhammer software. We have that every year and, as in previ...
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Devin Rorabaugh

Applying Communication Time: Let’s Talk About Your Impulse Result/Event Relationships

  I have received questions from clients using AFT Impulse where they ask something like "I closed this valve. Why is the maximum pressure spike way over there and not at the valve?" This comes from years of developing a "common sense" adapted to steady-state flow. With steady flow, a change between states of equilibrium has a local effect tha...
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Trey Walters

A Trillion Dollar Waterhammer Problem? Oh My!

An article published this month in the AWWA Opflow trade magazine relates that America has a trillion dollar problem with our municipal water distribution system due to pipe failures. This information is old news to the water industry. What is novel about this article is that it suggests the issue is largely caused by waterhammer (see Stop Costly W...
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Trey Walters

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

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?
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Trey Walters
Yes, the link in the blog now points to the full papers here: http://www.aft.com/learning-center/technical-papers... Read More
Tuesday, 24 July 2018 14:47
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Trey Walters

What is Pogo and Why On Earth Would Anyone Want To Suppress It?

The time was almost 30 years ago and it is fair to say I was not quite out of the "still wet behind the ears" stage for an engineer. I had been working in industry for about three years and I was just given a project that would change my career direction and, in fact, my life. The project? I was assigned to evaluate a new concept Pogo suppressor on a cryogenic rocket engine liquid oxygen (LOX) feedline. 

How did I end up getting assigned this project? Well, I had a few things going for me at that stage of my career. Firstly was that my company division was on a massive hiring spree. Since I had been hired three years earlier my division had doubled in size. Fortuitously for me, that meant I was now in the upper 50% of seniority. Secondly, I had just had a performance review and I had casually told my immediate supervisor during the review that I would be interested in learning about waterhammer should the opportunity arise. Thirdly and finally, I had demonstrated a knack for solving tough analytical problems. What that meant is that I was in the enviable position of having my supervisors assign me to any problem that was out-of-the-ordinary and otherwise unusually difficult. The new Pogo suppressor was such a problem.

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Trey Walters

The Knowledge Quest: Connecting With Fluids Education at Universities

This week was not a typical week for me. For the first time in 30 years I found myself in not one, not two, but three university classrooms. Each classroom was in one of Colorado's excellent engineering schools.

I had a chance to come face-to-face with about 140 students in classrooms this week and several professors. A number of positive things came of the week which I will summarize below.

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Trey Walters

Hurricanes and the Art of Computer Modeling

Hurricane Irma ravaged the Caribbean Islands and the state of Florida. Sixteen days prior, Hurricane Harvey ravaged the coastal area of Texas. Weather experts said this was the first time in recorded history that two Category 4 hurricanes made landfall in the United States in the same season. Each hurricane caused billions of dollars in damage and impacted millions of people.

Especially in Irma’s case, there was considerable discussion of the computer modeling used to predict the path and strength of the hurricane. As I have worked in computer modeling for most of my 30+ year career, this piqued my interest and I decided to educate myself a little more on the topic as it relates to hurricanes.

The first resource I pursued is one of our software developers here at AFT, John Lindsay. John has an undergraduate degree in Meteorology and a Master’s degree in Computer Science. John is a self-described weather geek who has a weather station at his home. We talked about weather modeling and he gave me some links to read further, which I did.

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