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AFT Blog

Welcome to the Applied Flow Technology Blog.
Trey Walters

Secret Variable-g Feature in AFT Software? Yep, And it is Now Visible to All

When I wrote AFT Impulse 1 back in 1996, I slipped in an undocumented feature to make it capable of modeling the first waterhammer project I did in industry. Since then, this feature had a secret (i.e., undocumented) way of being enabled. AFT Impulse 8 will be released any day, and we have finally made this feature accessible to all. In the User Op...
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Trey Walters

You gotta see this! New multi-scenario graphing and animation in AFT Impulse 8

Really? Another blog about features in AFT software? Yes, really. And there is a good reason for it. Because this new feature in AFT Impulse 8 will change your life. Well, it may not change your life, but it will forever change how you do your waterhammer analysis. I am talking about the new multi-scenario graphing and animation feature. This brand...
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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 that...
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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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Recent Comments
Guest — Colin D.
Is there anyway to get the complete papers? All I'm seeing are the Abstracts. Regards, Colin, DuPont Engineering... Read More
Tuesday, 24 July 2018 14:25
Trey Walters
Yes, the link in the blog now points to the full papers here: http://www.aft.com/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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