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Trey Walters

The Future of Engineering - Part 1

May and June are the time for graduations in the USA. My third son graduated from high school this month and will be pursuing a major in Aerospace Engineering. My oldest son is finishing his third year in Mining Engineering and my second son has started into a Mechanical Engineering major. Engineering education and the future of engineering is a frequent discussion topic around our home. So what is the future of engineering? Well, it is safe to say that a knowledge-based society like today's society will always need engineers. From that point of view the future of engineering is secure. However, more troubling to many engineers...
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juan leonardo
Thanks so much, for talk about this topic. This will help in my eduaction how engineer
Monday, 02 July 2012 17:18
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Ben Keiser

Sonic Choking: Flow Areas vs. Sonic Areas

AFT Arrow can be used to model various types of choking such as restriction choking, endpoint choking, and expansion choking.  A useful parameter in AFT Arrow’s output is the “Sonic Flow Area” and this is the flow area in which sonic choking will occur.  Comparing the sonic flow area to the actual flow area can help determine the margin between not choking and choking. The figure below provides a conceptual understanding of comparing various sonic areas to the actual flow area of a compressible system.  If one defines their system such that the sonic area ( A Sonic,1 ) is less...
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Ben Keiser
Hi Bogdan, The CdA value is essentially an effective flow area and it can typically be somewhere between 90-95% of the orifice ar... Read More
Monday, 04 January 2016 17:26
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Trey Walters

Where Did the Name "Arrow" Come From?

A frequently asked question at our training seminars - usually during a break or over lunch - is how we came up with the name "Arrow". More completely, the product is named AFT Arrow ™ and it is considered by many as the world's leading compressible pipe flow modeling software product. There is a similar story behind the naming of AFT Fathom ™ and I told that story several months ago in my post entitled Where did the Name Fathom Come From? The story behind the  Arrow name is rooted in the beginnings of Applied Flow Technology as a company. So let's...
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Applied Flow Technology

Automatic Renumbering

All of the pipe numbers in Fathom must be unique. When adding a pipe to a model, the new pipe number will be incremented based on the highest pipe number currently in the model. For example, you may only have 25 pipes on the workspace, but if the highest pipe number is 100, a new pipe will automatically be assigned number 101. After several iterations of deleting and adding new pipes, the numbering scheme may be reduced to chaos. AFT Fathom provides three tools to quickly and easily renumber pipes. They can be found in the Edit menu.   The Renumbering...
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Trey Walters

May the Force Be With You: Evaluating Unbalanced Forces Caused by Waterhammer

A common task among pipe stress engineers is to evaluate loads on pipe systems caused by waterhammer. Since AFT Impulse 4.0 was released our users have had the ability to calculate waterhammer-induced unbalanced forces for use in any pipe stress analysis application. In addition, our users can create specially formatted transfer files for direct use in CAESAR II and TRIFLEX . However, the process of calculating such forces in AFT Impulse and then applying them in pipe stress software is not as straightforward as it sounds. Our customers have asked for assistance in this process. I have teamed with Jim Wilcox of...
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Applied Flow Technology

Calculating Energy Costs

AFT Fathom and AFT Arrow have the option to include energy costs in the Output. To utilize this option, first open and fill out the “Cost Settings” window which can be opened from the Analysis dropdown menu. Next open the specification windows for the pumps that you would like to calculate energy usage for, and select the option to “Include Cost in Report” from the “Cost” tab. After running the model, you will be able to review the new cost data in the output.  The cost report is configurable in the Output Control window.      
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Ben Keiser

Problems With Heat Exchanger Specified Heat Rate In Constants?

Using “Specified Heat Rate In Constants” for the thermal model of heat exchangers can often cause problems in system models.  The reason why is because this thermal model type causes the heat exchanger to act like an “assigned heat input” junction as does an assigned flow junction does for providing constant flow rates.  Another problem is that this thermal model can cause unrealistic temperature changes across a heat exchanger.  When the heat rate is specified and the mass flow rate and heat capacity are calculated based on the system solution, the temperature change will be whatever is required to maintain the...
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Des Aubery
Very useful tip. Thank you. In many heat-exchangers, the relationship between heat-transfer & flow-rate would have a curve with c... Read More
Wednesday, 10 April 2013 09:37
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