AFT Blog

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...

Trying to design and analyze piping systems can be a complicated, and difficult task for engineers. This was especially true before the advent of easily accessible computer technology. Hand calculations required hundreds of hours of painstaking work, by entire teams of people. Great care had to be taken to ensure the reliability and accuracy of the results. Human beings do make mistakes, after all.

In today’s engineering world, there are a multitude of computer tools designed to make the design process simpler, faster, and more reliable, such as AFT’s family of analysis products. AFT products revolve around graphically based, drag and drop interfaces that makes creating a computer model of piping systems quick, and easy. Being able to create simulation models with little effort, however, can be a bit of a double-edged sword.

The majority of steady-state, incompressible hydraulic models made in AFT Fathom that we see as Applications engineers typically converge very rapidly. However, every once in a while, that occasional AFT Fathom model arrives in our Support inbox that just won’t converge. At first glance, passing a graduate level course in compressible flow without ever missing an exam question may seem more likely than getting to the source of the convergence issue in one of these typically-monstrous models (like in Figure 1), but the tips below show that determining and correcting the problem preventing convergence is frequently straightforward and much easier than...