AFT Blog
The Opposite of Good Vibrations - Evaluating FIV, AIV, FIP Guidelines from AFT Fathom and AFT Arrow
Learn how to use AFT Fathom and AFT Arrow to help calculate the Likelihood of Failure (LOF) for Flow Induced Vibration (FIV), Acoustic Induced Vibration (AIV), and Flow Induced Pulsation (FIP) in accordance with Energy Institute Guidelines to avoid v...
It's a Pump! It's a Turbine! It's a Pump as Turbine!
Pumps and turbines may serve opposite purposes, but fundamentally, they operate under the same principles. Both pieces of equipment convert between usable work and fluid energy, and both often use an impeller to make the conversion. Differences betwe...
What Is Transient Analysis?
You're tasked to perform a transient analysis of a piping system and it would be really helpful if there was a good software tool out there to help you. Well, you've come to the right place because AFT has great solutions! ...
Know Your Pump & System Curves - Part 3
In the final "Know Your Pump & System Curves" blog series, I am going to discuss the complexities behind pump vs. system curves for systems with pumps in series and parallel configurations. Multiple pumps in series configurations are relatively s...
Digital Twin – Identical or Fraternal?
When I was a child, I was jealous of twins. I thought how cool it would be to have a twin. I had twin cousins a few years older than I was that I saw on a frequent basis. I always got them confused. Which one was Roger, and which one was Ronny? A buz...
That Valve’s Got Character – Applying Pre-defined Characteristic Curves
Valves are often oversimplified during modeling. Understandably, defining a valve with its range of Cv at various open percentages requires much more information than an engineer may have during the initial design phase. However, just like handbook d...
In this blog, we dive further into pump and system curves for complex systems. The examples include demonstrating system curves changing over time and when multiple system curves exist for a single system with multiple pumps in different locations of the system. Let us re-visit the multi-branched system example from the previo...
Flow going backwards through a pump? Then the pump starts rotating in reverse? Where the heck is the check valve to stop the flow? These are all great questions (which I will answer later in this article). Theodore von Kármán and Robert Knapp were working on these questions in the early 1930's. Most engineering students encounter von Kármán in thei...
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 ...
For gas systems flow is driven either by a pressure difference, or by a turbomachine. AFT Arrow allows users to model turbomachines such as fans, blowers and compressors. For this blog we'll talk about what differentiates these three options, and how to model them using AFT Arrow. Definitions and Types Fans, blowers and compressors all...
With 54 peaks over 14,000 ft (4270 m) in elevation, the state of Colorado has many ways to get high. And rich. Once upon a time the path to riches was found underground, not on the peaks. During the 1870's mining towns began to emerge in Colorado. Colorado was definitely the "wild west" during those days! The mines operated over the next 20-30 year...
While thinking in terms of pressure is often intuitive for engineers, thinking in terms of head can be more challenging. You may be surprised by the number of cases and questions that come to the support team here at AFT about the basic definition of head, and how it relates to hydraulic modeling. Let's get back to the basics with how head is defin...
Nations handle the interaction between their government and the business/industry sector differently. Earlier in life I was firmly of the belief that governments should not interfere with business/industry as, despite the best of intentions, they typically make things worse and only add on bureaucracy without providing any net value in the end. As ...