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...
The process of sizing a pump for the application of priming a piping system as well as for normal operation is slightly more involved than if the system was already primed and the pump was to be sized for a liquid full system. For a system priming application, the intermediate elevations at high points in a piping system are relevant in regard to the pump that is used. If a pump is not able to generate enough head in order to overcome the high intermediate elevation points in a system, then the pump will provide no benefit to the system, even...
When evaluating the hydraulic behavior of aged pipelines and/or pipelines that are exposed to particularly corrosive or dirty fluids, building and running a hydraulic model is a great first step, but more engineering may be required. This is because, over time, residue in the pipeline fluid can buildup in the pipeline and essentially decrease the pipe inner diameter while increasing the roughness of the pipe’s inner surface. Corrosion can also change the roughness of the pipe’s inner surface. Engineers know that these changes due to buildup and corrosion in the pipes can significantly affect the hydraulics of the system, so while building a hydraulic model of the system is essential to evaluate its behavior, calibrating the model to account for these changes can be just as important in getting an accurate representation of your system. AFT Fathom and AFT Arrow offer a goal seeking module to assist with this calibration process with one data set of flow data. To understand how this can be done, visit Dylan’s blog. My blog here will take Dylan’s discussion one step further and discuss how AFT Fathom and AFT Arrow can be used to calibrate a hydraulic model with not just one but with multiple data sets using the GSC (Goal Seek and Control) module.
I am writing this from over 30,000 feet (actually 35,001 feet/10,667 meters according to my video map) over the Atlantic Ocean and on my way to Europe. The recent vote of the UK citizenry to leave the European Union (EU) is a hot topic at the moment (what everyone has been calling BREXIT). And I just finished reading yet another article on BREXIT. So I decided to digest some of what I have gathered in an article and here it is.
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...
My career has been spent applying engineering principles to predict the future - specifically how actual or planned physical systems will respond in the future. Such predictions of course allow engineers to make decisions on safety, energy, environmental impact, and cost. Physical systems follow the laws of physics. Compared to other areas of human endeavor like oil, politics, and the economy, engineering is easy.
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...