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Welcome to the Applied Flow Technology Blog.
Scott Lang

Planning for Success by Predicting Failure – Maximizing Reliability During Pump Selection

What comes to mind when you hear the expression “planning for failure”? For some, it carries the negative connotation that failure is the direct result of a design – intentionally or otherwise. Benjamin Franklin said; “If you fail to plan, you are planning to fail!” and I believe he would agree that any good plan addresses potential failures. In fact, not "planning for failure" as an element of a system is essentially failing to plan and therefore inviting unexpected and unmitigated failures. Life Cycle Cost One of the many reasons to avoid failure when possible is to reduce cost. When a...
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Scott Lang

Reaching Equilibrium: System Energy Balance in AFT Fathom and AFT Arrow

AFT Fathom and AFT Arrow both have the powerful ability to model heat transfer in pipes and heat exchangers , allowing you to represent these critical features of temperature-sensitive systems in your hydraulic model. However, without being able to see the affect heat transfer has on an entire system these features would be of limited usefulness. One of the most powerful aspects of AFT’s implementation of heat transfer is that energy is balanced across the entire system. For example, you can observe changes in pump or control valve operation when adding heat transfer to a remote part of a system. Looking...
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Scott Lang
Hi Alan, We would like to help get your model up and running - if you send your model along with some more details about the prob... Read More
Wednesday, 03 April 2019 17:08
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Erin Onat

Let the Heat Flow: Modeling Heat Transfer in Pipes in AFT Fathom and AFT Arrow

Among the many talents of AFT Fathom and AFT Arrow software is the ability to model heat transfer. While a major source of heat transfer is heat exchangers , this blog will address heat transfer that occurs in pipes. First, for the basics: Just what is heat transfer? Well, heat transfer occurs when there is a temperature difference between two objects at different temperatures. As all engineers know, the common theme of physics is that matter and energy alike travel spontaneously from higher, more chaotic surroundings to calmer, lower energy situations (not unlike the stereotypical engineer), and heat transfer is no...
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Applied Flow Technology

Bring the Heat: Modeling Heat Transfer in Heat Exchangers in AFT Fathom and AFT Arrow

Heat exchangers are some of the most expensive pieces of process equipment, so it is crucial that their pressure losses and heat transfer are well understood. AFT Fathom and AFT Arrow allow users to model heat exchangers within their piping systems. Pressure loss models include input K factors, resistance curves, or tube bundle information. When energy balances are being considered, users can choose between 11 heat transfer models in AFT Fathom and 12 heat transfer models in AFT Arrow to best meet their hydraulic modeling needs. While AFT Fathom and AFT Arrow can also model heat transfer in pipes , this...
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Erin Onat

Are you for real? Understanding and Troubleshooting Artificial Transients in AFT Impulse

Around this time of year with Thanksgiving just around the corner, I always reflect on the truly endless list of things I am so grateful for. While this list is by no means exhaustive, some of these things include my loved ones, my awesome job at AFT, the bounty of pumpkin-flavored treats that sweeten up my fall-time snacking options, and of course, AFT Impulse’s detection of artificial transients. While the dreaded Warning message that an artificial transient triggers can cause any engineer’s stomach to turn, I’ll explain why every AFT Impulse user should add this feature to his/her list of things...
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alen
Thank you Erin for drawing our attention to this issue. One thing that I miss here is HOW to resolve the issue. How to specificall... Read More
Tuesday, 14 November 2017 09:52
Erin Onat
Thank you for taking the time to read my blog and to give me some feedback! The model discussed in this blog involves a somewhat... Read More
Friday, 01 December 2017 01:40
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Applied Flow Technology

Using Branch Junctions to Model Desuperheaters

Superheated steam is often used in mechanical power applications, such as driving turbines. For heating or industrial processes, however, saturated steam is more efficient. Desuperheaters are used to lower the temperature of superheated steam, so that it can be more effectively used in industrial processes. A desuperheater lowers the temperature of the steam by injecting water. Now, the question is, how can you model a desuperheater within AFT Arrow? AFT Arrow  is a single-phase program for compressible flow, so it cannot model liquid water. Conveniently though, there is a feature built into the branch junction that can model a desuperheater. You...
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Erin Onat

Closing the Loop on Modeling Closed Loop Systems in AFT software

For several users of AFT software , it goes pretty predictably: first you place a pressure junction, then maybe a pump, then some sources of pressure drop including valves and heat exchangers, and then the model is finished off with another pressure junction. Of course, this is greatly oversimplifying the process and the vast array of systems that are modeled with AFT software, but here’s my point: most users are more familiar with modeling open systems that include individual pressure junctions located both upstream and downstream of the system. But what about modeling closed systems? The truth is that modeling closed...
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Kevin
Really nice article! This greatly simplifies the thought process around closed systems. I think it's worth noting that the absol... Read More
Monday, 18 September 2017 22:05
Erin Onat
Kevin, The clarification you pointed out is vital, and I have updated my post to be more explicit about this point. Thank you for... Read More
Tuesday, 19 September 2017 16:54
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