AFT Blog
Welcome to the Applied Flow Technology Blog where you will find the latest news and training on how to use AFT Fathom, AFT Arrow, AFT Impulse, AFT xStream and other AFT software products.
Coming Soon To a Computer Screen Near You: AFT Impulse 5 - Act Now To Get New Features at Old Prices
Want to know what new features are coming? Read on! Waterhammer Modeling of Slurry Pipe Flow AFT Impulse 5 will offer a new add-on SSL module for modeling slurry flow in piping systems. Why is this important? The AFT Impulse 5 SSL module will offer the first commercially available waterhammer modeling of settling slurry piping systems. The slur
From There to Here - The History of AFT Impulse Up Through the New Version 5
From the very beginning AFT Impulse was a world leader. AFT Impulse was first released in November, 1996 which made it the first visual, drag-and-drop waterhammer modeling software for Microsoft Windows (see below). AFT Impulse 1 in 1996 - the First Graphical Waterhammer Software for Windows Those of you who are familiar with AFT Impulse today a
Now For Something Completely Different: The New Graph Guide in AFT Impulse 6
As we started to test the new graphing features we were concerned that users would struggle to access these features. So we came up with an idea that turned into the Graph Guide. What is the Graph Guide, you ask? Well, in simple terms the Graph Guide is an interactive, hierarchical guide built into the Graph Results window which assists the user
AFT Impulse 20th Anniversary: A Perspective From the Original Impulse Developer
The day-to-day demands of getting AFT going as a company was slowing down the completion of AFT Impulse. So I turned over the day-to-day tasks to the two engineers I had at the time. One of the two, Jeff Olsen, is still with AFT as V.P. Technology. I took my computer and huge CRT monitor home to work in my basement for some long and uninterrupted
How AFT Impulse Can Help Engineers Comply With ASME Codes
Summary Engineers are often responsible to design systems to comply with codes and standards. In recent years codes that apply to waterhammer and surge pressures have become more prominent. Increasingly AFT Impulse is being used to help engineers comply with such codes. Once AFT Impulse has calculated the maximum pressure due to a transient event,
Modeling a submerged pump in AFT Impulse
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 fi
Model Specialty Valves Accurately with AFT Impulse 5
Applied Flow Technology is proud to release a new version of AFT Impulse, now at version 5. AFT Impulse 5 encapsulates all of the new interface and navigational enhancements from AFT Fathom 8, as well as a considerable breadth of new and improved technical features. One such feature is our newly enhanced Relief Valve Junction. A relief valve can st
Estimating Pump Inertia, Specific Speed, and Four Quadrant Data within AFT Impulse 5
An excellent new feature of AFT Impulse 5 is that it is possible to estimate the pump inertia, specific speed, and four quadrant data sets directly within AFT Impulse 5! No more need to perform external spreadsheet calculations for these estimates. In addition to that, AFT Impulse 5 can use the entered pump and power/efficiency curve to perfo
Reduce run times with AFT Impulse “Infinite Pipe” feature
One of the drawbacks of modeling complex systems is the corresponding run times that they come with. No one wants to run a model for several hours when it can be run in minutes or even seconds. In some cases you may be able to significantly decrease the run time by a factor of 100! There is a powerful feature in AFT Impulse called the “Infinite Pip
Using Liquid Accumulators in AFT Impulse
Many engineers are familiar with gas accumulators and their ability to aid in surge suppression modeled in AFT Impulse, but what about liquid accumulators? Liquid accumulators are different from gas accumulators in that they are assumed to be liquid full and do not have any gas that can compress and expand in order to dampen pressure spikes caused
Combining Pipes in AFT Impulse to Decrease Model Run Times: How Resistance Curves Are Merged into Pipes to Increase Pipe Section Length
They say that time is of the essence, and as engineers, that couldn’t ring truer! AFT pipe flow software is there to help engineers save time by more safely, efficiently, and rapidly designing and analyzing their piping systems. AFT Impulse, Applied Flow Technology’s waterhammer tool, helps engineers analyze transient incompressible flow behavior t
AFT Impulse Over the Years
November 21, 2016, marks AFT Impulse's 20th anniversary! Below is a timeline that captures a few of the most significant ways it has evolved from Version 1.0 to Version 6.0.
Taking the Pulse of Fluid Systems: Introducing the New AFT Impulse PFA Module
The problem is not whether pulsation is steady-state or transient. It is whether the frequencies that are excited by the pulsation are at or near the acoustic resonant frequencies of the fluid system. If so, there can be problems. API 674 defines the allowable pulsation limits for positive displacement pumps. AFT will soon release the new PFA modu
Are you for real? Understanding and Troubleshooting Artificial Transients in AFT Impulse
I tend to 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 drea
What Do the New AFT Impulse 7 and Bordeaux, France Have in Common?
I think this is the third monthly blog article I have written this year from an airplane over the Atlantic Ocean. Truly I do not save my monthly blogs for airplanes. I am really busy most all the time these days. Being on an international flight means having a long, forced time disconnected from the Internet and more free time than normal to write.
Applying Communication Time: Let’s Talk About Your Impulse Result/Event Relationships
I have received questions from clients using AFT Impulse where they ask something like"I closed this valve. Why is the maximum pressure spike way over there and not at the valve?"This comes from years of developing a "common sense" adapted to steady-state flow. With steady flow, a change between states of equilibrium has a local effect that t
Looking to relieve pressure? Let's talk about Relief Valves in AFT Impulse.
In any complex piping system, one of the most serious scenarios considered during a safety or HAZOP study is over-pressurization. If the pressure in the system reaches a high enough pressure, rupture can occur, leading to expensive repairs, significant system downtime, and even loss of life. In most cases, proper use of relief valves can mitigate o
Multi-scenario graphing and animation in AFT Impulse
Really? Another blog about features in AFT software?Yes, really. And there is a good reason for it. Because this new feature in AFT Impulse 8 will change your life. Well, it may not change your life, but it will forever change how you do your waterhammer analysis. I am talking about the new multi-scenario graphing and animation feature. This brand,
Five Fantastic New Features for Fast Fluid Transients: Impulse 8
At the time of writing, AFT Impulse 8 is right around the corner. We are proud to boast of new capabilities to give you an even better user experience with transient analysis.AFT Impulse 8 showcases new features never seen before, and ones only hinted at with the releases of AFT Fathom 11 and AFT Arrow 8. Here, we have laid out the top 5 new featur
AFT Impulse: A Quarter Century as a World Leader
A few weeks ago, a major milestone was passed when AFT Impulse experienced it's Silver Jubilee - which is another word for 25th Anniversary. On November 21, 1996, AFT released the world's first visual waterhammer modeling software for Windows. This is significant for a few reasons including a reminder to me that I am getting really old! At the mome
How does AFT Impulse model transient cavitation
The term transient cavitation is thrown around frequently when talking about the effects that transient events have on piping systems. It is widely and correctly understood to be something that can be harmful to pipes and pipe system components, but how to predict and calculate transient cavitation is not something that is as equally understood. I
Know Your Surge Codes and Use AFT Impulse: ASME B31.4
Unnecessary Background Codes and standards are not sexy topics, nor are they liked by the rebellious at heart. Whether you love or hate them they are a part of the world and aim to make it a safer place. One of the largest organizations to compose standards is the American Society of Mechanical Engineers (ASME). They have been around si
Should Engineers Always Perform Waterhammer Analysis of New Pipe Systems?
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 of a story one of our AFT Impulse customers told us about ten years ago. The engineer was an experienced waterhammer engineer and was fairly new to using AFT I
Rockets are Pumping Systems Too - The Aerospace Heritage of AFT
Jeff and I worked together at General Dynamics Space Systems Division in San Diego, California in the late 1980's and early 1990's. I worked there from 1986-1992 on cryogenic rockets on what came to be known as the Atlas I, Atlas II, Atlas IIA and Atlas IIAS. These Atlas rockets had an Atlas booster rocket which was fueled by room temperature RP-1
Get More Flexible With Your Fluids
Here at AFT we are always looking for more ways to bring more convenience and accuracy to our model files. One of the ways we are doing this is with NIST REFPROP, the new fluids database that we have incorporated into AFT Fathom 10 and is coming soon in AFT Arrow 7 and AFT Impulse 7. Unlike Chempak, REFPROP is included at no additional cost to
When Pipe Stress Analysis Meets Waterhammer Hydraulics: New Waterhammer Guidelines for Engineers
I am sitting on an airplane at this moment somewhere over the Atlantic Ocean and I am excited. Something that has been in the works for 22 years will happen next Monday, July 16 in Prague, Czech Republic. That is where the ASME PVP 2018 Conference will happen and I get to make a presentation.Last year I helped AECOM, an AFT customer and AFT Impulse
And, Not, Or - Starting Transient Events with Complex Logic
AFT Fathom XTS and AFT Impulse have long been able to start events like pump trips or valve closures when a certain condition is met in the system. For example, a valve can close when a tank is full, or a pump can trip when the flow is too low. However, complex systems often have multiple conditions that can cause an event. The pump may trip when t
A Story About Fluid Communication
Jack, Ryan, and Sally are piloting a small research vessel on a remote river. While distracted by news of the Mars 2020 Perseverance rover (successful landing!), their vessel crashes and begins capsizing. After their initial panic, they are dismayed to find the collision has taken out their communications equipment.In some quick thinking, Jack find
Safety
As President of AFT, I often hear from our customers about how one of AFT's software products has helped them solve a problem or made their lives easier. Sometimes I'll notice something in the news and think how AFT's products COULD have helped avoid a problem. Every month, I'd like to share these insights with you in hopes that we can all work tog
Where Did the Name "Fathom" Come From?
The story behind the Fathom name is intimately tied to the story behind the founding of Applied Flow Technology as a company. So let's go back to 1993. AFT Fathom started as a hobby in 1992 while I was working in the power industry as a research engineer. But it was not named Fathom and I was not planning to start a company. As a hobby, I was plan
AFT Around the World
In early October, I conducted a 5-day training seminar in Lima, Peru. There were seven different companies represented from Peru and Chile. It is always interesting to see the variety of applications for AFT software and Peru was no exception where many of the engineers are involved in mining operations. Peru is a leading producer of copper, gold,
My 50th Anniversary Visit to the Site of John Glenn’s First American Flight Into Space
By good fortune the NASA contractors at Kennedy Space Center had scheduled an AFT training class last week, and I traveled to Florida to teach the class. I took some time to tour the Space Center and Cape Canaveral one evening and was able to visit Complex 14 where the launch took place. The rocket booster for Friendship 7 was a General Dynamics A
Resources to Validate AFT Software
Users regularly contact us asking for information to assist them in validating AFT software. The formality of the validation requirement ranges from customer's self imposed internal requirements to rigorous validation as required for work in the nuclear industry. Fortunately, AFT provides extensive reference material for validation and, what's more
Model Pump Curve Families With Multiple Pump Configurations
You've probably modeled pumps using curve data from the manufacturer. In conjunction with specifying a name reflecting the pump make and model and saving pumps to your component database, selecting and using these pump junctions in your system models is fast and easy. Often, however, a make/model pump will have not one set of head/pressure, efficie
How to Fill as Quadratic
Filters and screens impose a pressure drop that varies with flow rate. The variation is non-linear, but manufacturers will often provide only one data point for pressure loss at the design flow rate. Using a single point, or constant pressure drop, can produce significant inaccuracies in your model. With this in mind, AFT offers the “Fill As Quadr
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 us
AFT Fathom 8 and the Future of AFT
What does all of this mean for the future? The new, more modern look and feel of AFT Fathom 8 is based on a new underlying architecture. We will be working hard to move all of our other products to this architecture as quickly as possible. Our best guess is that AFT Impulse 5 will be available in first quarter of 2013 and AFT Arrow 5 will be avail
World Languages and Waterhammer
For those who are not familiar with waterhammer, it is a transient phenomenon that occurs in liquid pipe systems when some event causes a departure from steady-state flow. The English language term waterhammer is a bit confusing. As it has the word "water" in it, it implies a process involving water. But the English term has historically been appl
What do NASA, DuPont, GDF Suez and the University of Arkansas know about AFT software that you may not? Watch it here!
DuPont The first story talks about how AFT Fathom helped DuPont solve a serious operational problem in three newly designed slurry systems. I co-authored a technical paper along with DuPont's Dan Wood to describe this to industry. AFT Impulse Video NASA The second story is about how AFT Impulse has been used by engineers at NASA's Kennedy Sp
Why You Should Care About AFT's New User Groups
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 among AFT software users that User Group meetings be held regularly. As a result, we have another Houston User Group me
Who Cares About the Surge in "Funny" Fluids?
Funny, non-Newtonian fluids are often broken into two categories: Homogeneous fluids which encompasses non-settling slurries where the fluid and solids behave in an aggregate, homogeneous manner Heterogeneous fluids which encompasses settling slurries where the fluid and solids behave somewhat independently The applications where non-Newtonian fl
Show Junction Locations
One of the many new features in AFT Impulse is the ability to show junction locations in profile plots. This can be enormously helpful when analyzing large, complicated systems. When enabled, all junction locations are identified by a vertical bar with a junction ID flag at the top. To show junction locations, click on the button in the toolbar.Sho
The Two P's: Why You Should Care That AFT is Celebrating Its 20th Year
First is because 20 years in business means that AFT software is proven.Second is because of the prizes we are giving away this year. Twenty of them no less!Come along with me while I elaborate on what AFT has achieved in the last 20 years. And explain more about the two P's.A Vision for the VisualThe last 20 years has been a long and exciting jou
Benefits of the Discrete Gas Cavity Model
AFT Impulse 5 now includes a second cavitation model option: The Discrete Gas cavity Model (DGCM). So, what is it and how is it different from the existing cavitation model? This article will provide a very high level overview. The method of characteristics (the finite difference basis for 1D transient flow modeling) assumes a constant wave speed f
Making Use of the Quick Access Panel
With the release of AFT Fathom 8 and AFT Impulse 5, there is an incredibly useful new feature available on the Workspace called the "Quick Access Panel". This feature allows you to quickly and easily work with several useful features of the software in one area such as the Scenario Manager, Pipe and Junction Inspection, Workspace Overview Map
Why Gases Are More Complicated Than Liquids: And How the New AFT Arrow 5 Can Help
Today it is no longer necessary to take short cuts. But all too often we see engineers doing just that. AFT Arrow is AFT's gas flow simulation software and it will be celebrating its 20th anniversary next year. Just last week I had a conversation with an AFT Arrow user from a well known engineering firm who was required by a client to use gas mode
Efficient Modeling Using Pipe Property Features
Complex piping networks can often be simplified using two powerful features available in AFT Fathom 8 and AFT Impulse 5. Under the “Pipe Properties” window, the “Fittings and Losses” tab and the “Use Intermediate Elevations” feature on the “Optional” tab allow the user to specify several fittings and elevation changes that otherwise would be input
Low Pressures, High Stakes
When building a model using AFT Impulse there is always a trade-off between detail and efficiency. Late last week, two very powerful features were highlighted that allow users to maintain a high degree of detail while being more efficient. But what happens when a system is under specified and these features are improperly implemented? In December o
Pointing the way with AFT Arrow 5’s “Search” Feature
AFT Arrow 5 was recently released and has several wonderful new features in store! One of the most powerful and largest time saving features is the new glorious “Search”. Located in the toolbar, “Search” allows for the quick locating of Junctions or Pipes much like a search engine finds a website. Where can I find it? “Search” has become a st
When Pipe Flow Modeling Is Not Enough
Over the years I have attended many conferences, forums, technical committees and customer meetings where I have met many engineers with different areas of domain expertise. These domains include vibration measurements and analysis of pumps, statistical reliability and MTBF analysis of pumps, analysis of installed pump instrumentation, variable fr