Trying to run a model and running into convergence errors? Here are a few common tips to help with model convergence for AFT Fathom, AFT Arrow, and the steady state modes for AFT Impulse and AFT xStream. Though these tips will not work for all models, they have helped with many of the steady state convergence cases that have come through the AFT su...

Have you ever been working on an interesting project where you get into the zone by picking up so much momentum in the work you are doing? But then, all of a sudden you hit a brick wall in your progress and cannot help but feel the pain of all that momentum coming to a screeching halt? You are not alone, in fact, fluids experience something ve...

Non-Newtonian fluids are something almost every elementary school student is familiar with. Mixing cornstarch and water to create a liquid that acts as a solid is an experiment which has captured the attention of children (and adults) for generations. The Discovery Channel show Mythbusters even showed Adam Savage walking across a tub of cornstarch ...

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...

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...

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...

In June 2020, AFT's Reinaldo Pinto presented the webinar Calculating Transient Forces for Pipe Stress Analysis. The webinar focused on generating unbalanced forces due to surge in AFT Impulse and exporting them to CAESAR-II. During the webinar, 28 questions were asked. Below are the responses.  Download the presentation: www.aft.com/...