AFT Blog
Scuba divers and casual swimmers alike are all too familiar with the discomfort (and sometimes outright pain) experienced in their ears as they descend deeper into the water. This discomfort is experienced for good reason: for each 33 feet you descend into the water, you experience considerably more pressure (about 1 whole atmosphere) due to the hydrostatic pressure of the water. As the pressure of the surrounding water increases, the air trapped in the middle ear remains at atmospheric pressure, but the pressure in the outer ear is significantly higher, which puts significant force on the eardrum. Anyone who has ever...
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....
Previously, we talked about the Graph Guide and how to create Stacked Graphs. Another way to see the interactions between parameters is to show them on one graph with dual Y-axes and a common X-axis scale. I am going to again start with the AFT Impulse model, ‘Pump Startup With Event Transient.imp’, which is installed in the Examples folder, and use the ‘One Pump Start With One Running’ scenario. In the previous blog, we used a Stacked Graph to examine the pressures and flows at two valves (J6 and J9), which opened during the simulation. This time, we will put them...
Using graphs that are stacked on top of each other is a great way to see the variation of several parameters at once and how one interacts with the others. There are several ways to create stacked graphs using the new graphing features in AFT applications, which I will cover here. I am going to start with the AFT Impulse model, ‘Pump Startup With Event Transient.imp’, which is installed in the Examples folder. I am going to use the ‘One Pump Start With One Running’ scenario. We will first compare the flow and pressure in the pipe path from the Supply...
The primary way to view results when using Impulse is through graphical data. With the release of AFT Impulse 6, the power of the graphing features has been greatly increased. With this enhanced capability comes additional complexity. It is a kin to the power and complexity of in-dash radio consoles in modern cars compared to the old stereo in my old Ford Pinto. To help users navigate the new capabilities of this powerful graphing tool, we have developed a ‘Graph Guide’ which points out the steps to accomplish many of the common tasks in creating, modifying and keeping graphs. The Graph...
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?
AFT Impulse will be celebrating it's 20th anniversary later this year in November. I was the original software developer of AFT Impulse back in 1996 and was still actively writing code up through AFT Impulse 4. So AFT Impulse is near and dear to my heart. Within the next few days we will be releasing AFT Impulse 6 and it will have some new and extremely powerful graphing features (more on that below).