Category Archives: Fluid Dynamics

Transferring Forces from Fluent to System Coupling

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A common question I hear from System Coupling users, particularly when using an operating pressure in ANSYS Fluent other than atmospheric pressure, is “Which pressure is used when transferring forces from Fluent to System Coupling and how do I change it?”.

The simple answer is that the forces passed to System Coupling are based on the gauge (or solved) pressure in Fluent by default. More accurately, the gauge pressure minus the Reference Pressure is used, but the Reference Pressure is zero by default so this is equivalent to the gauge pressure.

Before going further let’s review the Operating Pressure, Reference Pressure and gauge pressure.

The Operating Pressure in Fluent should be set to a typical absolute pressure in the system. Pressures set at boundary conditions are then specified relative to the Operating Pressure. Often the Operating Pressure is set to the absolute pressure at an outlet, and then a relative (gauge) pressure of zero is set at the outlet boundary condition(s). Continue reading →

Setting Up a Simple Flow Simulation (Part 2)

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At the end of February, I blogged about how I had the pleasure of talking with Desktop Engineering magazine’s senior editor Kenneth Wong via podcast. He had a simple challenge for me: For a structural engineer who is just beginning to work with fluid dynamics, outline the points important to CFD flow simulation. He also asked me to explain how to avoid pitfalls when setting up the simulation and what to look for when analyzing the results.

That podcast focused on the simulation setup. More recently I met again with Kenneth, and this time he wanted information about how to run the simulation and analyze the results to extract key engineering information.

flow simulation pipe valveRemember, we are looking at a ball valve design. In this design, the flow pushes on the valve when it is partially open, which could deform or move the valve enough to make it leak. The analysis simulates flow behavior inside the valve to determine whether or not the valve leaks.

First we focus on how to ensure that the solution process has gone the way it should. Continue reading →

Canadian Ingenuity Reduces Risk of Powerhouse Flooding

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In Canada, we are proud to contribute to reducing the global carbon footprint by exploiting renewable energy sources that are readily available, like hydropower. However, it is important to manage this resource responsibly and cost effectively by reducing risk of failure and increasing efficiency. Using fluid dynamics, structural mechanics and thermal analysis, Kawa Engineering Ltd. delivers a broad range of services to the hydropower industry (as well as others) to allow customers to design and test many parts of these facilities before they are built. As part of celebrating Canadian Engineering Month, here’s a recent interesting project that developed a location for a powerhouse.

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3-D geometry used for flood analysis. Elevations are relative to sea level.

We used engineering simulation to help locate the powerhouse close to a waterfall but in a spot with minimal flood risk. If flooding occurred in the powerhouse, it would be extremely costly. Finding a proper location also means that there is decreased need for additional components to protect electrical equipment (generator, turbine, switch box, etc.) if flooding occurs; it determines the cut and fill required for construction; and lessens construction resources. Continue reading →

Setting Up a Simple Flow Simulation

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A couple of weeks ago, I had the pleasure of conversing with Desktop Engineering magazine’s senior editor Kenneth Wong for a podcast recording. He had a simple challenge for me: For a structural engineer who is just beginning to work with fluid dynamics, outline the  points important to CFD flow simulation. Additionally, he asked me to explain how to avoid pitfalls when setting up the simulation and what to look for when analyzing the results.

My first thought was that, well, there are great classes, training and free YouTube videos available. Give me a couple of hours and I can turn a structural-expert-but-CFD-newbie into a CFD user. Kenneth understood all this, but his biggest challenge was yet to come. He asked me quite seriously, “And can you get an engineer on the right track in a couple of minutes?”

*** Mission Impossible soundtrack playing inside my head ****  Sure! Let’s do it!

Continue reading →

Reactions Are Everywhere – Learn About Modeling Reacting Flows

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image of Learning text on a keyboard ANSYS Webinars and EventsOur existence depends on reactions. They are all around us. Driving to work, we convert the hydrocarbon fuel through a combustion reaction into water vapors and carbon dioxide. In the case where you have those fancy hybrids or electric cars, you still need that electrochemical reaction to take place to draw current and run the electric motor.

We breath air. The oxygen in air helps in burning the glucose in our body and provide us with energy. So, be it a very complicated engine or a biological system like humans, reactions are everywhere. Continue reading →

Bleeding-Edge Technology

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The engineering simulation community is getting used to the role of ANSYS products behind bleeding-edge technologies, be it serving the exorbitant performance demands of F1 racing cars or extreme precise modeling of the nonlinear elasticity curve of dipole coils or designing entrance window for LHC Beam Dump Line at CERN. But I don’t usually drive a F1 car to the office nor does the existence of Higgs Boson affect my morning breakfast taste, despite being the building block of everything. As one of many tech-hungry people working, or rather living, on the edge and always anticipating what is next, I started thinking about where it all started and where are we now?

Have you ever thought the technology that was born more than 40 years ago, out of Astro Nuclear Research Labs, that has now penetrated into our routine life at such levels that we usually fail to think twice about it? The use of engineering simulation in the design or development of home appliances, cell phones, toys, etc. is well known. So let me draw your attention to a few very routine examples where we usually do not think that simulation matters. Continue reading →

Last Minute Gift for the Holidays: How About a Robot Dragonfly Created with ANSYS Software?

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Desperately searching for a gift for my nephew Dominick, I came across this article about a flying robotic Dragonfly that the Air Force has spent more than $1 million developing.

My first thought was ‘what kid wouldn’t want a flying insect that weighs less than one AA battery equipped with a camera that can be operated with an iPhone?’

My next thought was ‘Wait, a minute, I’m not shopping for myself.’

My third thought was ‘I’ve recently read about this device being created with ANSYS software.’

The Georgia Institute of Technology submitted this story and image to our 2013 Hall of Fame competition that has concluded. (Results coming, stay tuned.)

MAV Wing CFD

Here is what they told us: Continue reading →

Four Out of Top Six F1 Racing Teams Powered by ANSYS

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image of Red Bull Race Team

Team Red Bull Racing poses for the end of season team photo during previews for the Formula One Grand Prix of Brazil at Autodromo Carlos Pace on November 22, 2012 in Sao Paulo, Brazil. (Photo by Vladimir Rys)

If you’re like me — a passionate fan of Formula 1 — you were probably on the edge of your seat during the last race of the season in Brazil, during which either the Red Bull of Sebastian Vettel or the Ferrari of Fernando Alonso could have won the championship. After a season of 20 F1 races, the fact that the contest was so close is a measure of the margins these teams work with. Anyone who has been to a race and witnessed these race cars firsthand knows exactly how close to the edge the cars and drivers are.

F1 Vehicles Most Technologically Advanced

F1 vehicles are the most technologically advanced in the world; they need to adapt each year to changing regulations. This often results in a team redesigning the car’s roughly 4,000 components to meet the demands of performance and safety. But not only that, engineering teams are continually improving performance between races — often having only two weeks between races to make a performance impact. With lap times for the leading cars differing by fractions of a second, improperly executing these changes from one circuit to the next can be the difference between being on the podium and not scoring any points. Continue reading →