AFT Blog
It is true. New Jersey is a barrier in Spain. I saw it with my own eyes. Bear with me and I will explain.
When I travel internationally I find the people, cultural and language differences fascinating. Last month I was fascinated once again. My blog last month was written while on an airplane as I travelled to Europe (see my July blog When Pipe Stress Analysis Meets Waterhammer Hydraulics: New Waterhammer Guidelines for Engineers). Before going to the ASME PVP conference in Prague (check out this video one of our staff made) I stopped in Spain for 4 days. While there I was fortunate to visit the location of an AFT Impulse project by one of our customers that was a Platinum Pipe Award Winner this year. This case study was published in April. See AFT Impulse™ Matches Data For Pumping Station Check Valve Closure. That pump station photo in the case study is where I visited. Below is a photo of me and the PPA winner David Lozano Solé of AQUATEC – SUEZ Group. For those interested, this project is being presented as a technical paper by David at the 2018 Pressure Surges Conference in Bordeax, France in November. I will be there to help and also present two other papers of my own. So where does New Jersey come into this?
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.
We are all shaped by our experiences as engineers. Our early experiences as young engineers are especially influential.
I first worked in the aerospace industry for five years and then the nuclear industry for two years. At each of these companies we relied heavily on a handbook written originally in Russian by a Russian engineer. I am talking about the Handbook of Hydraulic Resistance by I.E. Idelchik. This book is my "go to" book on any unusual pipe system configuration hydraulic calculations and, especially, with calculations at tees and wyes.
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.
In case you have not noticed, rockets can be really loud. Sound suppression on vertically launched rockets (and the Space Shuttle, back when it was flying) is more important than most of you would think. And for a different reason than most of you would guess.
Every so often I get to talk about my first job which was in the aerospace industry where I first learned about sound suppression systems. Today AFT software is used on several of these systems by our customers in the aerospace industry as well as NASA.
The flowrate of water used in the sound suppression process is enormous. Which is why they are often called "deluge systems".
There are many (six!) ways to define a pump transient event in AFT Impulse. This gives you great flexibility in creating a model that behaves the way you want it to. One thing true for all pumps is that they must be started at least once. Pump startups often cause significant transient effects on the system so you may wish to model this with AFT Impulse. Even narrowing your pump transient down to a startup, there are still four models left to choose from: Without InertiaStartup With Inertia and No Back Flow or Reverse SpeedStartup With Inertia - Four Quadrant, Known...
To define any transient event in AFT Impulse or AFT Fathom XTS the application must know when it begins. To do so, the user should know how time and event logic is approached in AFT’s transient solvers. In this article, we will discuss the three different time bases used in the applications, the selection of a single or repeating event, and the many possible triggering events that can start the user defined transient. The user defines these items in the Initiation of Transient section of the junction’s Transient tab. The requirements for each junction can vary, but the general approach applies...