As the original developer of AFT Arrow, I consider it as one of my babies. This month it is all grown up and now 25 years old. Back in March we came out with the latest new version AFT Arrow 8 – just as the COVID-19 crisis was emerging.
Those who have taken an AFT Arrow seminar which I have taught (at least fifty classes and counting!) have likely heard how of all the AFT software products, I am most proud of AFT Arrow. Why is that?
Five years ago I wrote about the "behind the scenes story" as part of AFT Arrow's 20th anniversary. That blog outlines the technical hurdles I overcame in creating AFT Arrow.
While AFT Fathom was AFT's first software product, and AFT Impulse is our most complicated, both of those products essentially use textbook methods for pipe network calculations. For AFT Fathom the textbook was Jeppson's Analysis of Flow in Pipe Networks and for AFT Impulse the textbook was Wylie and Streeter's Fluid Transients in Systems.
For AFT Arrow the textbook for single-pipe calculation methods was Saad's Compressible Fluid Flow. However, there was (and still is) no textbook for compressible flow in pipe networks. As explained in the AFT Arrow 20th anniversary blog, I had to come up with my own techniques to solve pipe networks. I had used Saad's textbook when I took an undergraduate elective class in compressible flow. I adapted Saad's single-pipe compressible flow methods and Jeppson's network methods for incompressible flow into a completely new calculation technique. Then, for good measure, I threw in some novel iterative approaches to handle special cases of sonic choking – with some help from Jeff Olsen, AFT's V.P. Technology.
That is why I am most proud of AFT Arrow. Its network calculation techniques are not found in any textbook and had to be developed by hard work and some good old ingenuity. And it has nailed sonic choking calculations for over two decades now.
