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AFT Blog

Welcome to the Applied Flow Technology Blog where you will find the latest news and training on how to use AFT Fathom, AFT Arrow, AFT IMpulse, AFT xStream and other AFT software products.
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

Should Engineers Always Perform Waterhammer Analysis of New Pipe Systems? Part 2

Two years ago this month I wrote this blog article: "Should Engineers Always Perform Waterhammer Analysis of New Pipe Systems?". This was a popular blog. It was written from the fluid dynamic engineer's perspective. Last month I was teaching an AFT Impulse training seminar and this same question came up during the class from an astute attendee. However, the question came more from a pipe stress engineer's perspective. And I realized that the answer to the question is not necessarily the same for a pipe stress engineer. Thus came the idea to write a Part 2 to the previous blog. A fluid...
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Trey Walters

When Pipe Flow Modeling Is Not Enough

Within the world of pumping system specialists there is a wide range of areas of domain expertise. I was reminded of this earlier this month while attending the AFT Calgary User Group meeting sponsored by AFT's Canadian channel partner. One of the invited speakers, Jordan Grose of Beta Machinery, used several areas of domain expertise to solve a waterhammer problem in the field. I will discuss more about Mr. Grose's presentation later in this article.

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Trey Walters

World Languages and Waterhammer

The demand for our AFT Impulse waterhammer modeling software and associated training seminars has been growing steeply in recent years. I frequently travel internationally to teach  seminars on waterhammer. When I do I make it a point to find out what the engineer's local language calls waterhammer. For those who are not familiar with waterhammer, it is a transient phenomenon that occurs in liquid pipe systems when some event causes a departure from steady-state flow. The English language term waterhammer is a bit confusing. As it has the word "water" in it, it implies a process involving water. But the English term...
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Guest — Eddie Bosman
The Afrikaans word for waterhammer is "waterslag" (Afrikaans is one of the many languages in South Africa).
Wednesday, 28 November 2012 15:28
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John Rockey

Jumping Specification Windows

In the process of making specification changes to a sequence of pipes or junctions, one may find it easier to jump from one pipe (or junction) to the next without closing the current specifications window. This can be accomplished by clicking the “Jump” button in the specifications window. Clicking the Jump button will open a dialog where the next pipe or junction number can be selected. Once the selection is made, clicking on the jump button will advance the existing specifications window to the selected pipe or junction number. To make things even faster, pressing F5 within an active specifications window...
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Applied Flow Technology

Graph Sets

In all of our core products (Fathom, Arrow, Impulse, Mercury, Titan), we offer the ability to save graph sets. This has the potential to save a lot of time when reviewing multiple graphs of different parameters. In order to define a graph set, first construct and customize the graph you would like to review. Then open the “Select Graph Data” window from the View menu and click the button “Save Set As…”. After entering a graph set name, click ok, and you have just created a graph set! At this point you can modify any parameters in your model, re-run the...
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