AFT Blog
Pulsation in fluid systems...Is it steady-state or is it transient? Well, it is both. Kind of. Pulsation causes periodic transients that are regular in nature and thus considered steady-state. It can be called "steady-state pulsation".
Have you ever finished running an AFT Impulse model and then received the following Warning message shown in Figure 1 and then wondered what it means? During a waterhammer analysis, the flowrates are constantly changing all throughout the system, therefore, the velocities and Reynold's numbers are also constantly changing. The friction factors will also be constantly changing during the transient. By default, AFT Impulse will use the friction factors that are obtained during the steady-state analysis and then use the same friction factors during the transient and they will be assumed to remain constant. Since it is possible for the flowrates...
November 21, 2016, marks AFT Impulse's 20th anniversary! Below is a timeline that captures a few of the most significant ways it has evolved from Version 1.0 to Version 6.0.
Twenty years ago today I was working desperately on putting the finishing touches on AFT Impulse 1.0. At the time, AFT was a pioneer in every sense of the word. AFT was the first and only company developing visual, drag-and-drop pipe flow modeling software for Microsoft Windows. And AFT Impulse was set to become the world's first visual waterhammer software for Windows. We already had orders for AFT Impulse before it was complete, such was the demand!
A little over 30 years ago I made a mistake. At the time I was a busy undergraduate student in mechanical engineering in California. Some students put together an official weekend trip for ME students to the Hoover Dam that included a special tour of the dam geared towards engineers and engineering students. I remember having tons of homework to do and decided not to go on the weekend trip. That was a mistake and I have regretted it ever since.
One of the most common causes of waterhammer in pipelines is a valve closure. As the valve closes, the flowing liquid is forced to stop, resulting in a transfer of kinetic energy to potential energy, which ultimately causes a pressure increase. If this increase in pressure is large enough, extremely severe damage can result in the pipeline. Engineers frequently mitigate this waterhammer by selecting a valve that closes slowly enough to prevent the pressures from getting too high. However, a valve that closes too slowly can cause problems elsewhere in the pipeline or result in other undesirable outcomes in the process....
Safety is a primary consideration in engineering design. Safety for people is always paramount. Safety for the environment is an ever-growing focus of engineers. Any engineer worth the name would feel devastated if their engineering effort failed for some reason to protect people and the environment. One of the things engineers rely on to make system designs and operations safer are analytical tools like those developed by Applied Flow Technology (AFT). How does AFT software make the world a safer place?