AFT Blog

AFT Arrow is a highly accurate and powerful compressible flow analysis tool and rather than solving various compressible flow correlations, AFT Arrow is simultaneously solving the fundamental mass, momentum, energy, Equation of State, and Mach number equations.  Although AFT Arrow accurately calculates the fluid physical properties throughout the compressible pipe network, there is also a high level of complexity associated with these calculations. We have seen several models that have various convergence issues and there is a common troubleshooting technique that solves the majority of these issues.  This technique is simply changing the specific heat ratio accuracy option from “High” to...

Many of you work for organizations located outside the USA or with a presence outside the USA. Getting timely answers to your sales and support questions wherever you are located is important in order for you to support your projects and operations. AFT Employees and Channel Partners join together for a picture straight out of the "Old West." You may not know that AFT has a network of 36 channel partners around the world that assist us in providing this kind of support. We travel frequently to visit them and they also often visit us in the USA. This year on...

We’re getting closer to our 4th Channel Partner summit. For us in AFT, it’s a very special occasion since it gives us the opportunity to personally thank all our Channel Partners for their great effort in helping AFT become the worldwide number 1 option for hydraulic solutions. Starting with the hotel chosen for the Summit, this event will be not only be a three day working session where future marketing strategies will be discussed, it will also be a Summit seasoned with enjoyable surprises. At AFT, we know that fun and work are not mutually exclusive and this will guide our...

In AFT Impulse you can directly model a submerged pump. First, you will define your pump data exactly as you would normally, however you will only draw the discharge piping and not a suction piping. After doing this, you will check the box “Submerged Pump” at the bottom of the Pump Specifications Window. You now have an additional required input field. The “Suction Pressure” can be entered as a Head (HGL) or a Pressure. When entered as a Head (HGL) value, this value is the actual liquid elevation in the supply reservoir. When entered as a pressure, this is the actual...

Do you ever wonder who the people are behind AFT? Do you wonder what our plans are for the future of our software products? Do you ever wish you could talk directly to AFT staff and communicate new features you would like to see? Do you ever wonder who else uses our products in the geographic region around you? If you answered yes to any of the above, you may want to look into attending an AFT User Group meeting. Last October we held our first User Group meeting in Houston. We had 24 attendees. The consensus was that there was a desire...

The ability to specify default input parameters is a feature that is common to all AFT software products . Diameter, Friction Model, and Design Factors can be specified by default for pipes. Input properties for Junctions are specific to each junction type, so the only common default property is elevation. The default input options are found in “Parameter and Unit Preferences”. In general, this feature makes model building faster and more efficient. The user should, however, be aware of how this affects the “Status” of pipes and junctions. The “Status”, to which I am referring, is the green light to run...

The question of whether waterhammer analysis on new pipe systems is optional or required does not have a definite answer. In some cases it is clear - such as when the pipe system is being designed in compliance with ASME code (see How AFT Impulse Can Help Engineers Comply With ASME Codes ). But in many cases it is up to experience and judgment whether or not to perform waterhammer analysis. One of the issues complicating this question is that waterhammer events have a tendency to be non-intuitive. Thus even experienced engineers using intuition can be led astray. I am reminded...