AFT Blog
Users and potential users of AFT software frequently ask how they can expedite the model input process so that they can get the results they need as rapidly as they need. I’m pleased to report that AFT software has an abundance of features that make the model input process tremendously efficient: global pipe and junction editing, copying input data from other pipes and junctions, and finally, importing data using the Excel Change Data parameters spreadsheet (which is what we are discussing in this blog). The Excel Change Data feature works by importing data from an Excel spreadsheet populated according to a...
This week I was in Las Vegas at the 2016 MINExpo. AFT had a booth at the show and I hoped to publish this during the show and call it a "live" report. Alas I did not get it completed and the show ended yesterday. Hence it is "almost" live.
Previously, we talked about the Graph Guide and how to create Stacked Graphs and Dual-Y graphs. With AFT Impulse and with AFT Fathom’s XTS module, a great way to see how parameters change over time is through animated graphs. For the purpose of continuity, 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 blogs, we used a Stacked Graph and a Dual-Y Axis Graph to examine the pressures and flows at two valves (J6...
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 new features in AFT Fathom 9 was the ability to model equivalent lengths instead of K factors for various types of fittings. Since AFT Fathom's existence, the standard K factor loss models have been used to quantify the pressure losses across a fitting such as an elbow, a valve, etc. One of the reasons why the K factor method is very useful is because it is broad and applicable to a wide range of different fittings. However, the equivalent length method is also a way that engineers will typically quantify the losses through their fittings and they will...
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.
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...