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Best OSS CFD Package For High School Physics?

timothy posted more than 4 years ago | from the why-not-stop-at-algebra-I? dept.

Education 105

RobHart writes "I am teaching a 'physics of flight' unit to grade 11 Physics students. Part of the unit will have the students running tests on several aerofoils in a wind tunnel. I also want to expose them to a Computational Fluid Dynamics package which will allow them to contrast experimental results with those produced by the CFD package. There are a number of open source CFDs available (Windows- or Linux-based are both fine), but I don't have much time to evaluate which are the simplest to use in terms of setting up the mesh, initial conditions, etc. — a very important issue as students do not have much time in this unit." Can anyone offer insight about ease of use for programs in this niche?

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Orbiter (0)

Anonymous Coward | more than 4 years ago | (#32668496)

It's not OSS, but Orbiter [] may be what you're looking for.

Too Complicated (4, Insightful)

Thelasko (1196535) | more than 4 years ago | (#32668504)

I agree that CFD would be something nice to teach a high school student. However, unless this is an AP course, CFD is just too complex for high school students. Most people don't learn CFD until grad school.

Re:Too Complicated (1)

moogied (1175879) | more than 4 years ago | (#32668592)

Don't confuse 'Don't learn' with 'Can't learn'. They might be able to master it at all, but just some general exposure and some real high level usage can go a very long way in there careers. Two kids applying for a job, one has at least used CFD a few times and the other goes "No, but I can figure it out!" its pretty straightforward who is getting the job.

Re:Too Complicated (4, Insightful)

Chris Mattern (191822) | more than 4 years ago | (#32671302)

Two kids applying for a job, one has at least used CFD a few times and the other goes "No, but I can figure it out!" its pretty straightforward who is getting the job.

Yep. Neither of them. No place that uses CFD as part of the job is going to accept anyone who isn't a certified engineer with extensive training in its use.

Re:Too Complicated (0)

Anonymous Coward | more than 4 years ago | (#32672910)

Nobody said what the kids were applying for you moron. A CFD shop may, for example, have a summer intern gig. Summer internships for students interested medical imaging/physics, for example, don't require being accredited by the American College of Radiology.

Re:Too Complicated (0)

Anonymous Coward | more than 4 years ago | (#32674208)

I am an engineer and actually it comes down do you have a degree to did you take the class or not... And it doesnt take a genius to run a CFD, it takes one to interpret the results.

Re:Too Complicated (0)

Anonymous Coward | more than 4 years ago | (#32676616)

we just did.

they're called interns, engineers-in-training, apprentices, whatever word suits you.

Re:Too Complicated (1)

reason (39714) | more than 4 years ago | (#32686706)

I'm guessing they're 3rd or 4th year engineering or science undergraduates, though, not kids who would only have encountered CFD in high school.

Re:Too Complicated (0)

Anonymous Coward | more than 4 years ago | (#32679914)

Visual effects companies routinely have un-trained, non-certified, non-engineers using CFD.

Learning vs Exposure (4, Informative)

pavon (30274) | more than 4 years ago | (#32668790)

Just because they don't have the mathematical background to fully understand the models, doesn't mean that it is worthless to expose them to the concepts. Playing around with flow simulations and seeing how changes in geometry affect flow is fun, and can give them a feel for the basic concepts of aerodynamics. It will make the class more interesting, and encourage them to pursue physics or engineering as a career.

Re:Learning vs Exposure (3, Interesting)

Thelasko (1196535) | more than 4 years ago | (#32669794)

Playing around with flow simulations and seeing how changes in geometry affect flow is fun

Agreed, but I'm afraid that playing with CFD will just leave the students frustrated and convinced that physics doesn't work because they can't get CFD to work. I remember kids in high school, (even some in college) deciding that physics doesn't work because they couldn't get newton's laws of motion to match the results they observed experimentally. In reality, they didn't do their math correctly.

If the author want's to quickly demonstrate the principles of fluid mechanics to his/her students here is my plan:
1) Make sure they have a firm grasp on Newton's laws of motion.
2) Have them drop a paperclip and a coffee filter from the same height and measure how long it takes them to hit the floor.
3) Explain to them that this is the effect of aerodynamic drag.
I performed the same experiment in college physics. It's quick and effective.

Re:Learning vs Exposure (1)

spazdor (902907) | more than 4 years ago | (#32670298)

A college professor earned money by dropping a paperclip and a coffee filter? What kind of class was this, exactly?

Re:Learning vs Exposure (0)

Anonymous Coward | more than 4 years ago | (#32670374)

Dude, these are high school students, not kindergarteners.

Re:Learning vs Exposure (2, Interesting)

RJFerret (1279530) | more than 4 years ago | (#32670670)

I believe I saw that demonstration in elementary or middle school back in the 1970s or 1980s. In high school, our physics teacher showed a feather falling in a vacuum (much cooler). Get with the '80s already! ;-)

Re:Learning vs Exposure (2, Informative)

squizzar (1031726) | more than 4 years ago | (#32675064)

We did this in physics with a feather and a penny. Teacher had a big tall glass tube and a vacuum pump. I can't actually remember how they 'dropped' the items (I've dreamt up a system with a rod through a bung in the end of the tube, with the feather/penny stuck on the end by a small piece of blu-tack or similar, when you pull the rod up it knocks the item free from the end of the rod), but basically what you saw was the feather drop at the same speed as the penny (give everyone a stopwatch). Shows the aerodynamics, and demonstrates the way that gravity accelerates everything at the same rate, regardless of weight or density.

Re:Learning vs Exposure (1)

x0 (32926) | more than 4 years ago | (#32675962)

I've seen this same experiment in 'Rosencrantz & Guildenstern are Dead'... Feather and a bowling/bocce ball if I recall correctly. m

Re:Learning vs Exposure (2, Insightful)

DriedClexler (814907) | more than 4 years ago | (#32670872)

Unless they're learning something about *how* the model generates the results -- which takes a lot of explaining even if you minimize the formula use -- all they'll get out of it is:

"Magic computer gives magic results that we compare to some experiment."

The most important thing to impart on the students is not any fact itself, but that nature is not magic, that we use models to understand and predict nature, and that you can learn how the models actually work if you try.

Since they won't have the time to learn how the CFD software works, even at the pseudocode level, I don't see this as being a very helpful demonstration.

Now, in a perfect system, students would have all the background to jump right in to CFD by age 16, but we don't have one, and I don't think that this school is an exception.

Re:Learning vs Exposure (1)

Sethumme (1313479) | more than 4 years ago | (#32671030)

Even assuming you're correct that exposing a high school physics class to CFD software will fail at teaching them anything about fluid mechanics, you are still ignoring the more important benefit such exposure will have: sparking interest. I would bet that more than a few students would see the computer model and think, "wow! I wonder how other shapes would interact with airflow?". That right there is where the river of knowledge springs from.

Re:Learning vs Exposure (1)

DriedClexler (814907) | more than 4 years ago | (#32671346)

sparking interest. I would bet that more than a few students would see the computer model and think, "wow! I wonder how other shapes would interact with airflow?".

Right and he'll get interested in learning how to make shapes in the program and learning the magic number it spits out. Science is about learning how the "magic" works, not playing with its fruits.

Re:Learning vs Exposure (1)

Cwix (1671282) | more than 4 years ago | (#32672592)

Your right that it may not "teach" them a lot, but if it makes it fun they can realize that science isn't always boring. It just might be the thing that makes these students want to investigate a future in science or computers. Would any of us have ever been interested in computers if we hadnt seen what amazing magical things could be done with them? A few of us maybe, but honestly not very many I think.

Re:Learning vs Exposure (1)

rew (6140) | more than 4 years ago | (#32674760)

CFD is simple. for every timestep and every volume element, you calculate pressure and air (fluid) movement. If there is a pressure difference speed will increase (or decrease). When moving air can't go further, e.g. because it hits something solid, pressure increases.

In one paragraph I've explained the basics of CFD. This means you can teach it to high school students in an hour.

If they've played with say excel before, you can let them do a one-dimensional CFD in excel. (just pressure and speed.).

Re:Too Complicated (1)

vbraga (228124) | more than 4 years ago | (#32668866)

Some of the visualization stuff (membranes, vortex streets, convection cells can be beautiful) may, at least, motivate and interest a class, I think. Could maybe be used as an accessory material. Turbulence and a lot of interesting phenomena can be shown in a qualitative way. Non linear phenomena and their application to physics - a double pendulum goes a long way to show way the weather forecast isn't always right. Thermodynamics could be a lot less boring if show as simulations instead of ugly hand drawn ice cubes in a blackboard :)

I think there maybe a place for CFD in teaching physics - certantly it's not trying to get kids to simulate a jet turbine in ANSYS or developing their own FEM package. But it can illustrate and help kids see a lot of interesting things.

Visuals (1)

jd (1658) | more than 4 years ago | (#32671382)

For visuals, UIUC's Airfoil Data Site [] is a good place to start.

Re:Too Complicated (2, Interesting)

blair1q (305137) | more than 4 years ago | (#32668878)

That's what they used to say about computers.

But when I was learning to write Fortran in school in 9th grade, grad students were learning to write Fortran at the university across town, and making more mistakes and understanding it less than I was.

I would expect the CFD program that would suit this class is something that takes a simple grid input for the surface, simple initial conditions, then runs the flow and plots streamlines or vectors. No need to get into the theory behind the sim computations, just show how things flow across the surface.

If the kids are bright, they'll be ingrained with a desire to figure out (a) more about fluid flow, or (b) how a computer knows how fluid flows, or (c) both.

Re:Too Complicated (1)

jbengt (874751) | more than 4 years ago | (#32670958)

I would expect the CFD program that would suit this class is something that takes a simple grid input for the surface, simple initial conditions, then runs the flow and plots streamlines or vectors.

I don't believe there are "simple initial conditions" for CFD software.

Re:Too Complicated (1)

reason (39714) | more than 4 years ago | (#32686712)

Of course there are. Uniform initial density, zero (or uniform) initial currents, and a source at one grid point.

Re:Too Complicated (1)

Jurily (900488) | more than 4 years ago | (#32669022)

CFD is just too complex for high school students

Oh come on. These students have already learned natural language processing, is that not complex?

Perhaps it's the learning method that counts, not the subject.

Re:Too Complicated (3, Informative)

TheKidWho (705796) | more than 4 years ago | (#32669110)

Sorry, but trying to understand the results of a CFD simulation require a solid understanding of fluid mechanics and an understanding of shear stress, which in turn requires a solid understanding of calculus and differential equations.

Re:Too Complicated (4, Insightful)

spazdor (902907) | more than 4 years ago | (#32670422)

Similarly, no one has ever gotten good at baseball without first earning a PhD in ballistics.

Re:Too Complicated (0)

Anonymous Coward | more than 4 years ago | (#32671108)

nice :)

Re:Too Complicated (1)

0100010001010011 (652467) | more than 4 years ago | (#32670450)

Well, once you teach them calculus and differential and partial differential equations.

You can break them in with the Navier-Stokes [] equation.

Then break them the news that air foils don't lift because the air on top is "moving faster" but because it has to make minute angular accelerations. Since the air temperature doesn't change, the energy needed for drops out of the pressure. Tada, lift.

Or something like that.

Re:Too Complicated (0)

Anonymous Coward | more than 4 years ago | (#32670748)

Better start with a common-sense version of the kinetic theory of gasses. And a general-case graph of atomic atrraction x distance.

Will a flat sheet be lifted by a fast parallel airflow? Why?
Does an airfoil slow down topside airflow? How much? How? Why does it still work?

Physical work can be done with carton, fans, and thread or tape "vectors". Plus stuff.

Then let them at the computing simulators.

Re:Too Complicated (1)

Beezlebub33 (1220368) | more than 4 years ago | (#32677098)

No, you start with the Bernoulli principle, in a simplified form. That is, the kinetic energy plus pressure is a constant. You show them the really cool demonstrations of blowing over a piece of paper to make it go up, or the ball in the vacuum cleaner exhaust that stays in the exhaust despite perturbation. Then, you discuss why a curve ball curves. Then, you show them a simple pitot tube and put it in different velocities of air.

Then, you apply this to airfoils.

Then, you go to the NASA page and get their simulator FoilSim II [] .

Then, you point out that the simplifications that you made above can be improved on, but that the math gets really messy, and so we use the underlying physics equations and solve the numerically, using CFD.

Re:Too Complicated (0)

Anonymous Coward | more than 4 years ago | (#32671524)

not just differential equations, but most non trivial CFD calculations are Partial Differential Equations. That is grad level.

Re:Too Complicated (1)

Garridan (597129) | more than 4 years ago | (#32672622)

Oh bullshit. PDE's don't require grad level understanding. When I was an undergrad, I hacked up a simple first-order PDE solver (in PHP no less) for an extra credit problem I was doing at community college, and it did the job. It wasn't great, it wasn't robust or accurate or fast, but it was ridiculously easy to do. And I understood it fine. And I would have understood it fine as a high schooler, if I hadn't gotten kicked out of calculus.

Re:Too Complicated (1)

Goeland86 (741690) | more than 4 years ago | (#32672000)

I would argue that the only thing really required to get a fundamental grasp is to be able to read polar graphs and understand the concept of coefficient. Especially if you use a "specific CFD" tool, like XFLR5 - you don't need to understand ALL of what the variables are to understand Cl/Cd with t=alpha on a graph, same is true with GCm/Cd with t=Re.

Explaining the Reynolds number might be the most complex part of the class, actually. I mean, they're already doing wind-tunnel simulations to begin with - how hard is it to link what you see in your experiments with what a computer's trying to tell you? They can figure it out. If not, they wouldn't be in the class to begin with!

Re:Too Complicated (0)

Anonymous Coward | more than 4 years ago | (#32676714)

you're confusing engineers with scientists.

engineers use software tools all day everyday without having the first clue about the code that's producing the results, nor the complexity of the algorithms.

Re:Too Complicated (0)

Hognoxious (631665) | more than 4 years ago | (#32669768)

CFD is just too complex for high school students. Most people don't learn CFD until grad school.

I don't know where you come from, but we have a stage in between.

Re:Too Complicated (1, Insightful)

Anonymous Coward | more than 4 years ago | (#32670204)

I agree. Not only is CFD complicated, running experiments properly and analyzing experimental results are hard. What I fear is, you will end up asking them to contrast improperly measured results from a poorly run set of experiments against some computer output none of them has any understanding of. But the lesson learned is still going to be valuable, experimental and computational physics are hard.

Entirely irrelevant and wasteful answer. (4, Insightful)

LostMyBeaver (1226054) | more than 4 years ago | (#32674828)

Yes, I know this is Slashdot, but you got the first post and the first thing I read when I clicked on the to read comments is your somewhat counterproductive answer.

I would imagine that the instructor has already decided that the topic would match the students. If it were a regular level course, then it's likely he'd show a video on the topic and it would be good enough. Instead he's chosen to broach the math involved by attempting to simulate a fluid dynamics scenario.

In short, instead of assisting the teacher in his attempt to try and broaden the minds of ambitious youngsters, it almost appears that you're simply recommending that he stops doing his job, packs up and maybe instead teaches ABCs and 123s.

Let's face it, if he's a teacher who is "qualified" to teach a topic like computational fluid dynamics, I'd imagine that he wasn't hired to teach just the average "who gives a shit" student. There are enough useless teachers who wouldn't bother out there already. This guy at least makes the effort of trying to figure out how he can best accomplish the task of teaching a complex subject.

Please don't EVER!!!! stop an ambitious teacher from attempting to educate ambitious students in the future. Especially not under the premise of suggesting that it shouldn't be done.

Re:Too Complicated (0)

Anonymous Coward | more than 4 years ago | (#32678758)

agreed, you can make it work before the class, and then show it to the students(prepare some time, you are unlikely to get it working out of box)
cfd is not easy and simple, dont expect your students to handle this task, for 95% of them its over their heads and the rest 5% would have to spend unreasonable amount of time on it

foss - OpenFOAM
or you can pirate fluent, much easyer to get the results

Re:Too Complicated (1)

mikael (484) | more than 4 years ago | (#32678796)

Back in the 1990's, TV programming for schools (UK) used to have programs for A-level physics that covered this topic. The depth of explanation would be simply to have a cross-section of a various shapes (brick, sphere, aerofoil, triangle, flat panel) all in a wind-tunnel or wave-tank. Then smoke or dye would be added to show how much turbulence there was. The goal wasn't to explain fundamentals like curl, divergence, gradient fields, Eigen-vectors or Navier-Stokes equations, just to give an insight into why a wing provided lift, why a sphere would oscillate and a brick would not even glide.

Even then, all filming would take place in a university or an industrial research lab. It would still be too expensive for a school to provide a wave-tank or smoke box these days, so a computer simulation would be much cost-effective.

openFOAM (4, Informative)

Amigan (25469) | more than 4 years ago | (#32668520)

Check out openFOAM [] . You might find that it meets your needs.

Re:openFOAM (1)

Thelasko (1196535) | more than 4 years ago | (#32668574)

Check out openFOAM []. You might find that it meets your needs

Good answer. The price is certainly right.

The most widely used CFD software is probably StarCD. [] Unfortunately, it's probably cost prohibitive for a high school.

Re:openFOAM (1)

TheKidWho (705796) | more than 4 years ago | (#32668780)

Not really, CD-Adapco was handing out free licenses to students. I had a continuous 4 year license throughout college for StarCD. If you ask them nicely I'm sure they would provide you with a free copy for educational use.

Re:openFOAM (-1, Flamebait)

h4rr4r (612664) | more than 4 years ago | (#32669500)

And then they can make sure your files never work in anything else. Vendor lock in, what wonderful thing.

Re:openFOAM (1)

fotbr (855184) | more than 4 years ago | (#32669638)

And when you're working on the equivalent of "hello world" (ie, that specific file is never going to be used again), it doesn't matter.

Re:openFOAM (1)

TheKidWho (705796) | more than 4 years ago | (#32669996)

What the heck are you talking about?

The results you obtain can easily be exported as a plain text database or put into spreadsheet, considering they are tables with numbers for pressure, velocity, temperature, etc after all... Your 3D modeling data will most likely come in as some sort of open standard anyways. The files aren't nearly as important as the raw data.

I don't see the vendor lock in, care to clue me in?

Re:openFOAM (1, Informative)

Linux_ho (205887) | more than 4 years ago | (#32670352)

I don't see the vendor lock in, care to clue me in?

That wasn't an actual person you were responding to, it was one of the mindless "commercial software BAAAD" bots that inhabits Slashdot.

Re:openFOAM (0)

Anonymous Coward | more than 4 years ago | (#32670418)

They took our jobs!

Re:openFOAM (0)

Anonymous Coward | more than 4 years ago | (#32670714)

h4rr4r is a troll.

Re:openFOAM (3, Informative)

blair1q (305137) | more than 4 years ago | (#32668990)

Took some digging but I found a page where they actually show some pictures: []

You'd think they'd have some color somewhere on the home page, but OSS types rarely have a marketing clue...

Re:openFOAM (1, Interesting)

Anonymous Coward | more than 4 years ago | (#32670440)

openFOAM is very powerfull, i would say that it's too powerfull for the task

IMHO the minimum requirements to consider even using it are:

-C\C++ knowledge, to be able to write the 'problem statements' you need to be confortable with it.
-Obviously knowledge about fluid mechanics is required: Reynolds/Froude/Mach numbers, Bernoulli equation, steady/unsteady flow. This knowledge is required to be able to pose the problem. You will need a lot of knowledge about PDEs and boundary conditions, and the basics about the finite volume method at least.
-Basic knowledge about Meshing: What is a mesh, what types of meshes there are, what types of meshing algortihms and how do 'computers' mesh stuff. CFD takes a lot of resources, if you want to make a small simple cool movie about a flow meshing right your domain can be the difference between half an hour and half a month of computational time to arrive at the same numerical error.

Dont forget that openFOAM gives you back a LOT of data. You should also know what is it that you want to know (streamlines? path lines? Re/Ma/Fr number plots? vorticity? density? velocity profile? velocity gradient? pressure? pressure gradient? Drag forces? ...)

If you really want to do real CFD go for solidworks or nastran nx (yeah not real CFD but easier), maybe even ADINA or ANSYS (they are overkill but the interface lets you do some simple thing 'relatively' fast). There is also a PDEs Toolbox for Matlab that can do the trick, dont know if there is something similar for SAGE or Octave.

The best option for you i think is to use an inverse airfoil design program for RC Planes. There is one from MIT called Xfoil, and a lot of derivate versions. It let's you do subsonic simulations of airfoils (the geometry for many types of airfoils is already insade either with dimensions or parametrized so you are already saving time). Postprocessing is 'good enough', your students would be able to play with it a bit and see some results. If you are making RC Planes it can show them how starting from a given geometry or parameters, the program runs flow simulations at different attack angles and then 'improves' the airfoil profile iteratively till a certain criterion is met.

Anyways if you find an easy to use CFD program for basic calculations let us know.

Re:openFOAM (1)

Reibisch (1261448) | more than 4 years ago | (#32671998)

openFOAM is far too advanced for a basic intro to CFD. If you're hell-bent on introducing CFD in software form, you might be best off writing a simple fluid simulator and wrapping it with OpenGL or something. If you do incompressible flow with a simple structured mesh and a few editable parameters, you could probably be done in a few hours. And if you can't.. well, perhaps you aren't the right person to introduce such an advanced topic to highschoolers :)

Re:openFOAM (1)

jstults (1406161) | more than 4 years ago | (#32676858)

Rather that a full up Navier-Stokes solver (I was going to say openFOAM too), since it's a short section of a course, maybe just have them play with the NACA airfoil potential flow solver [] ; that's pretty neat. You can explain the simplifications to the governing equations between "real" CFD and potential flow, and show them that the simple models can still be useful in certain situations.

Re:openFOAM (1)

oojimaflib (1077261) | more than 4 years ago | (#32676916)

While OpenFOAM is certainly really powerful, it is short of a GUI* (except for results-visualisation), and might therefore be less than ideal. That said, it is simple enough to use with a walkthrough, and the fact that the interface is basically composed of text files should make it easier for students to get back on track if they go wrong (this is a big problem, for example, with teaching CFX). If the main focus of the work is going to be running an essentially pre-built model (which the students then rebuild and run) and looking at the results then it will be more than capable. It is also easy to investigate the effects of changing discretisation methods, solution schemes and the like. If you want it to be easy for students to perform tasks such as changing the angle of the aerofoil relative to the mesh, change the mesh resolution, etc. it may be less ideal as this will involve lots of messing around on the command line (and in text editors).

* In fact, there is a GUI available from, but this costs money (albeit not a lot). (no affiliation, I've never used this software and can't speak for its quality)

Re:openFOAM (1)

felesii (673184) | more than 4 years ago | (#32677092)

I have (tried) to work with OpenFOAM in the past, and I would very much not recommend it for someone who doesn't already have an intimate knowledge of CFD. It has a very steep learning curve and no GUI whatsoever anymore. It may be powerful and free, but it is not appropriate for OP's needs. As far as I can tell it was formerly a commercial code that was open-sourced, but they keep it as non-intuitive as possible to try to sell people on the $2000 dollar training courses they put on.

Code_Saturne (4, Informative)

thatcadguy (1346069) | more than 4 years ago | (#32668588)

I like Code_Saturne. It has a GUI that greatly simplifies the whole process. You can use SALOME to make the initial model and then mesh it, and also use it to visualize the results. All of these programs come precompiled on a live Linux distro called CAElinux. [] [] [] In any case, check out CAElinux. It's going to be the least hassle out of any of your choices because everything comes precompiled.

Re:Code_Saturne (1)

Yvan Fournier (1286876) | more than 4 years ago | (#32672356)

Code_Saturne is also now packaged in Debian unstable (as well as under Gentoo Linux and FreeBSD), so it should be even easier to install soon. I have also heard that a new version of CAELinux is under preparation, and that the SALOME platform is also being packaged under Debian (disclaimer: I am a Code_Saturne developer). Please use the new 2.0-rc versions found on [] instead of the old 1.4 version from the current CAELinux, as we've really improved the GUI and scripts, beyond the additional physical modeling capabilities that were added...

For post processing, ParaView or VisIt are much better than SALOME's current visualization module (a new ParaView-based module will be available in SALOME 6).

A few years ago, courses with Code_Saturne used pre-generated meshes, while students this year were taught to handle the whole process, including meshing under SALOME (actually, I believe both high-quality pre-generated meshes were made available and simpler meshes were generated by students, with the added advantage that the influence of mesh quality on result quality could be shown). The improvements in both SALOME and Code_Saturne's GUI certainly helped.

Still, the students that were trained are from some of France's top engineering schools, and I have no idea how simple high school students would cope. If the hands-on session is well prepared, it would seem feasible. Even if the students lack the theoretical background to really understand what the code does or judge the quality of a simulation, it can be an interesting experiment.

Try XFOIL... leave CFD for later (2, Informative)

Anonymous Coward | more than 4 years ago | (#32668646)

As an aerospace engineering PhD, I can tell you that CFD with mesh generation, turbulence model selection, numerical method selection, etc. is definitely above the level of your typical 11th grade student, even a gifted one. At best, you could have them run OpenFOAM tutorial cases, though it is highly doubtful that they would understand what is actually going on and would be able to say little more than "I've run a CFD code before, but I don't know what the results mean" at the end of the experience. There are number of panel-based aerodynamic analysis tools that would be appropriate, and of them, I'd say XFOIL is your best bet.

Re:Try XFOIL... leave CFD for later (1)

TheKidWho (705796) | more than 4 years ago | (#32668918)

On that note, JavaFoil is pretty nice. It gives you some decent numerical results for airfoil testing. I used it in one of my college fluids classes to help with some airfoil calculations. []

Re:Try XFOIL... leave CFD for later (2, Interesting)

Davorama (11731) | more than 4 years ago | (#32669478)

This is the advice you want to follow. Use XFOIL or some other panel method based program to analyze airfoils along side of your wind tunnel stuff.

You can talk about all the things it doesn't do well (boundary layer separation, transonic flow...) and show them some Color Fancy Drawings made by a more advanced simulation as an aside.

Re:Try XFOIL... leave CFD for later (2, Informative)

sirrunsalot (1575073) | more than 4 years ago | (#32670586)

This is the best advice you'll find here. I love CFD and I think any high school student could understand a good share of the basic physical concepts, but when you put it all together there's simply too much going on to yield much insight for all of the setup involved. If all you want is geometry in and pretty pictures out, then people have already listed a number of excellent packages, but spare the kids the details. A panel method is a good alternative, but be careful nonetheless.

Good idea, but very hard to do well... (4, Insightful)

Slipped_Disk (532132) | more than 4 years ago | (#32668726)

I like the idea of exposing your students to CFD packages, particularly the variation between experimental results & results off of a theoretical model. My concern would be that mastering a CFD package (or even become a basic user of one) is pretty time consuming. As others have pointed out you usually don't touch CFD packages until late undergrad or grad school.

Consider building the models yourself and running them as a demonstration rather than asking your students: They get the benefits of seeing what the software can do & being able to reference the theoretical data generated, but won't have to deal with the frustration/learning curve of CFD software.
If there's an interest you can offer an extra credit project where students design (or modify) a mesh & report the results.

Re:Good idea, but very hard to do well... (0)

Anonymous Coward | more than 4 years ago | (#32670494) - The Java Virtual Wind Tunnel. This is appropriate for high schoolers.

Re:Good idea, but very hard to do well... (1)

kcelery (410487) | more than 4 years ago | (#32673776)

This one JAVA Virtual Wind Tunnel is interesting.

Ubuntu, Elmer, not a hand-drawed cartoon... (1)

maxiste (835613) | more than 4 years ago | (#32669084)

But "Student package" include in ubuntu 9.10, 10.04 version for General physics and C.F.D. It's a python with clean interface, some add Tkinter interface, some add wxWidget or QT4 to run home-made modules, It give you a simple interface, similar to Wolfram-stylish framing where you can add yourself information, comment... even RPC server... I mean, walk through IT classe's to find out goods students looking "final-staging" to design couple of RPC-function from python instance from elmer where you can create a simple server to let student access to information, like modeling, matrix sets and simplify the work... Ubuntu distribution is simple, order the cd by mail, buy an extra usb-stick of coupels of Gb, and format it into ext2 while booting the Ubuntu cd-rom is done whithing hours if you try-it first, secondly add elmer or previous one with code-saturn. You can even look to trying python wiimote example to draw you example on-drawboards, being reflected on you computer... But Wii-remote not included Python is really easy to do...

CAELinux (0)

Anonymous Coward | more than 4 years ago | (#32669130)

OpenFOAM is included in a much broader package, CAELinux, which offers additional Open Source solutions that may be of interest to the education community, such as Scilab and Octave, replacements for Matlab. In addition to OpenFOAM for CFD, the package includes Salome for mesh generation (somewhat easier than OpenFOAM) and a GUI-based Code_Saturne for CFD analysis. CAELinux is a complete system, built on Ubuntu 8.04, such that it works right out of the box, no configuration required. It can be run from a LiveDVD or built as a second boot option on a Windows or other Linux machine.

As a trainee physics teacher... (1)

wjh31 (1372867) | more than 4 years ago | (#32669202)

As a trainee physics teacher for A-level students (age 16-19, i believe about equivilant to grades 11-12) i will be watching this thread with interest.

Some have suggested that we will not be able to teach this level of physics to this level of students. However if something comes up which can be used for simple attractive demonstrations then that would be great.

E.g in my course my students need to know the difference between laminar and turbulent flow, and fast move fluids will break into turbulent flow. If a simple simulation allows the demonstration of this then i feel it would help alot with that simple idea, and high achieving students will be able to just play around and see how fluids behave.

Thanks in advance to anyone who provides good links

San Le's Free FEA / CFD (1)

rwa2 (4391) | more than 4 years ago | (#32669246) []

I haven't used it, but I've used his related SLFFEA [] for a project before, and was surprised how easy it was to use.

Some OSS codes to consider (0)

Anonymous Coward | more than 4 years ago | (#32669278)

* OpenFOAM

Very capable CFD package with many features. Can read meshes created by gmsh, but also many other formats. Only runs on *nix systems. Very good parallel support. Rather steep learning curve, but doable.

* Gerris

Unconventional meshing process consisting of an tree structure which is automatically refined during convergence.

* Elmer FEM

Multi-physics package which includes a GUI, while the other two do not. (I have not had much luck with the GUI for anything other than easy initial setup of the case. After that it's back to the text editor) Windows binaries are available. Reads gmsh meshes, or can create its own from a simple file format. Can easily couple the Navier-Stokes equations with the Heat equation, Linear Elasticity, Electrostatics, etc for more complex scenarios.

JavaFoil (3, Informative)

louks (1075763) | more than 4 years ago | (#32669342)

Basically, this is similar to XFoil, which is the standard 2-D CFD software for beginning Aeronautical Engineers (after they made us write our FORTRAN77).

Since it is not 3-D, it runs MUCH faster and lets them discover the basics of pressure over an airfoil, which is the important part of wing design. The details of taper, sweep, tip shape, twist, and such are a bit too much for a high-school project. Surface area and aspect ratio are the simplest and most important criteria for airplane design. These values can be calculated on paper after coefficients of lift and drag are generated.

Javafoil can be run stand-alone or in an applet. It's free, and fairly straightforward to use.

Best of luck. I'd be interested to hear how quickly they catch on to the concepts. []

'Ease of use' relative (3, Interesting)

multimediavt (965608) | more than 4 years ago | (#32669422)

I've taught computational fluid dynamics and molecular dynamics workshops to university faculty members and can say this: You need to setup the examples for them to play with BEFORE class. There's really no such thing as an easy to use CFD or MD package, especially when looking at what it takes to setup initial conditions. I would strongly recommend that you do a good deal of the leg work, especially for participants that do not have the mathematical background or a background in fluid dynamics, period. It will only help you in the end.

This link [] will take you to lists of free and free-to-academics CFD codes, but the free ones are really, really bare bones in a lot of cases when it comes to UI. I would not turn high school students loose on these codes without pre-determined examples.


Anonymous Coward | more than 4 years ago | (#32669554)

Xfoil by Mark Drela at MIT. I've used this professionally. Fast, Accurate, and fast to pick up, (with guidance could probably have results inside half and hour)

FUN3D (1)

jd (1658) | more than 4 years ago | (#32669614)

NASA has several Open Source CFD packages. Unlike the ones developed by the regular OSS community (which may technically be superior), NASA Langley's CFDs are used by engineers there in real aircraft design. No matter what problems there may be (and there are sure to be some), they have to be "good enough" for real-world commercial aviation. That is certainly good enough for a physics lab.

The problem with other CFD packages is that even if they produce good results, unless you analyze the code, you can't be certain if the results are scientifically correct. Personally, I like programs like Gerris and some of the other packages out there, but I can't be certain of their correctness.

As a complete aside, there's a fascinating story emerging over amateur fusion scientists. Apparently, ITER expects amateurs to make some useful discoveries, and several amateurs have made claims of achieving some nuclear fusion events. This would put fusion technology in the same state as garage computing was in the early 1970s.

Re:FUN3D (1)

TheKidWho (705796) | more than 4 years ago | (#32670174)

<blockquote>As a complete aside, there's a fascinating story emerging over amateur fusion scientists. Apparently, ITER expects amateurs to make some useful discoveries, and several amateurs have made claims of achieving some nuclear fusion events. This would put fusion technology in the same state as garage computing was in the early 1970s.</blockquote>

Fascinating to a point, there is a large community of amateur scientists who have made what are called <url:>

Re:FUN3D (0)

Anonymous Coward | more than 4 years ago | (#32670406)

The problem with other CFD packages is that even if they produce good results, unless you analyze the code, you can't be certain if the results are scientifically correct. Personally, I like programs like Gerris and some of the other packages out there, but I can't be certain of their correctness.

FYI, OpenFOAM, Gerris, and Code Saturne are all GPL.

Re:FUN3D (1)

jd (1658) | more than 4 years ago | (#32671322)

Yes, they are, but that doesn't make them correct and it doesn't mean anyone can be certain of their correctness, unless they spend time analyzing all the code arcs and constructing the model they actually use (versus the model intended by the author(s)) and =then= comparing that model against the formulation of the Navier-Stokes equation within the specific parameters concerned. (Almost nobody implements the generic equations, any CFD you find is going to be a simplified special-case version.)

Now, if you were using CFDs to model how air flowed through a computer case, you probably aren't going to be worried if the numbers are a bit off. What matters is that there's no dead air and that there's a fairly high air-flow over the hotter components. In those cases, you don't give a damn about mathematically perfect models. If you want to model canal erosion, you don't really care that much if the actual erosion is going to be three feet further downstream, just so long as you get the general vicinity. Good enough works for these cases.

Airfoils - that's another matter. You need a much higher level of correctness, because you're dealing with a much more compact and much more complex surface. (You can download 1,500+ standard airfoils with specific characteristics - hardly necessary if this stuff was easy.)

I am getting old.... (0, Offtopic)

Itninja (937614) | more than 4 years ago | (#32669652)

The highest level science class available in my HS was AP Chemistry. It would have so cool to take physics in HS.

CFD or Load Analysis? (2, Informative)

riboch (1551783) | more than 4 years ago | (#32669720)

Are you looking for real CFD software for pressure distributions or are you looking for something that returns lift, drag, side and moments?

On the CFD side: OpenFOAM. Learning this is quite a bit of work because you need to work with meshing, boundary conditions, etc. But I would be very surprised you really want flow visualisation.

For loads: XFOIL or AVL (Athena Vortex Lattice, [] ). AVL allows 3D visualisation of loads, perturbations, etc. When it comes to a first iteration in aeroplane design this is first thing we use in academia and is quite nice. XFOIL is 2D and is used for analysis on an aerofoil. Both allow arbitrary geometries, but I believe both are strictly for inviscid flows.

What theories in particular are you trying to validate?

Here are two great CFD packages for airfoil sim (5, Informative)

vincentbetro (1840582) | more than 4 years ago | (#32670072)

I will be getting my PhD in Computational Engineering in August, and as a former university, high school and middle school math teacher, there are things that can be applied to teaching young students about CFD without them having all the mathematics background they need. I am the STEM outreach coordinator at the SimCenter, and I have a website [] which includes an Euler solver on a NACA 0012 airfoil with changeable parameters for students to study the various solutions based on mach, angle of attack, etc. It also does grid adaptation. There is a graduate student tutorial and a high school student activity. I have used it with precalc, calc, and physics students at local high schools. Please feel free to contact me at for anything else I can help with. Vince P.S. Another good (and longer running) package can be obtained from NASA Lewis and can be run on any platform: [] . Good luck!

X-plane flight simulator (1)

systemeng (998953) | more than 4 years ago | (#32670130)

The X-plane flight simulator has an aircraft designer module and it models the airfoils with simple CFD models AFAIK. It's also certified for use as a flight trainer if you have the expensive physical cockpit parts to build around the software.

Re:X-plane flight simulator (1)

Shotgun (30919) | more than 4 years ago | (#32671908)

Unfortunately, no, X-plane does not do CFD. You have to generate the airfoil's characteristics in something like X-Foil to create an airfoil file for the program. It is essentially a flat text file of lift coefficients vs angle of attack. Xplane breaks the lifting surfaces into narrow panels, and then adds up all the various lifts in real time.

CFD in real time would be way to computationally heavy.

Maximize the learning experience (1)

thor4217 (1834296) | more than 4 years ago | (#32670362)

Perhaps a good question is- will running CFD be a learning experience for your students? Will they just be blinding clicking options without getting much out of it? Perhaps they could interact with a CFD solution that you ran instead. They could still do a comparison to experimental results. I have found that simpler 2-D or other approximate codes offer better learning experiences that full-up CFD because changing options, creating geometry and viewing results is much simpler. Check out XFOIL and maybe ASWING: [] []

Airfoils (2, Interesting)

lbarbato (410651) | more than 4 years ago | (#32670456)

If you're looking for an airfoil simulator, you might try NASA's FoilSim II [] . "Elementary," student, and undergraduate versions are available, and the non-applet download gives an even more complete version that allows file output. While it's not a full CFD package, it may be good enough for an introduction to airfoil analysis. And while it's not open source, it is free and in the public domain (since it was government produced).

Also, if you're generally looking for open source physics simulations, you should check out Open Source Physics at []

In particular, a brief search there yielded the Tracker Air Resistance Model [] - a level appropriate simulation that lets students explore the air resistance of falling coffee cups with both viscous (linear) and drag (quadratic) models.

Nearly all of the OSP items have the source code available for modification of the models.

Fully Powered CFD ? Try Blade Element Momentum ! (1)

burni2 (1643061) | more than 4 years ago | (#32670566)

Well a CFD-System for just verifing wind tunnel tests might be a bit too much, but verifying lift and drag for such airfoils is possible.

This is based on my experience in the wind industry, so this means I'm refering to blades which consists of many airfoils attached to a rotor but the basic principles remain the same.

When dealing with windturbine aerodynamic simulations Aerodyn[3] implements the BEM[1] but BEM is based on MT[2] and can caculate Lift/Drag for Airfoils due to a certain wind either constant or
turbulent. Turbulent wind can be generated by Turbsim[5].

And if you don't want to stop there, with FAST [4] you get an "easy" design code for load caculations on a simplified turbine model,
with example simulation models like the NREL 5MW-Offshore Turbine.

In the wind industry CFD will not be used for caculating aerodynamic loads acting on the rotor and drive train, we use reduced theories like BEM[1] (which exists in various even spiced up versions, for things like dynamic stall, tower drag, tower shadow etc..)

CFD is taken into account when the blade design is going to be tuned, for example finding vortices which consume kinetic energy and generate certain unwanted noise levels.

And by the way all NREL-Tools are OSS.

Draw back -> you can't "see" the vortices unless using CFD.

[1] []
[2] []
[3] []
[4] []
[5] []

Gerris Flow Solver (1, Interesting)

Anonymous Coward | more than 4 years ago | (#32670630)

I recommend gerris flow solver for something that is fairly easy to use....

30 minutes after building it I had this:

and I think I spent more time figuring out how to build models in blender. It's not as powerful as openfoam, which is what I normally use now.... but its easier to get started with.

enGrid, OpenFOAM and others (1)

KIAaze (1034596) | more than 4 years ago | (#32670688)

For mesh generation (surface+volume meshing, boundary layer creation, etc):
enGrid: []
netgen (used as a library in enGrid): []

For the CFD simulations: []

Debian/Ubuntu packages: []

Highschool? (0)

Anonymous Coward | more than 4 years ago | (#32671740)

You should be happy students even know how to calculate integrals.

Re:Highschool? (1)

Beezlebub33 (1220368) | more than 4 years ago | (#32677298)

This is one of several comment about high school students and their abilities. My wife and brother are both teachers, and I help out with the science fair. Some of the things that the students are doing in high school are pretty amazing today. The gaussian curve of intelligence and dedication is amazingly wide, and the ones on the right side of the curve in terms of science are simply amazingly intelligent, hard working, and fascinated by learning. The underlying ideas and using the computer to do CFD is not too much to ask for many of these students. (The ones in the middle of the curve, and the ones on the left side of the curve, are not going to get it, but not everyone is going to be an engineer).

Being happy that they just know how to do integrals is not enough. Some of these smart kids would be bored to tears if they didn't have this sort of class and challenge. For them, doing something like this can be a positive life changing experience. In our state in the US, we are so concentrated on standardized testing that all the kids need to pass, that the ones that could pass in their sleep are being ruined.

X-Foil (1)

Goeland86 (741690) | more than 4 years ago | (#32671958)

X-Foil - hands down. Designed by MIT, you can download .dat files for airfoils to load them, create NACA airfoils, and output all sorts of polar graphs. If you're even more ambitious, look up XFLR5 on sourceforge - it does CFD over the entire surface of the aircraft in 3-D, as you can create a wing plan, tail surfaces and even a fuselage using curves. XFLR5 is great because of the visualizations you can get from it - including animated lift/drag/pressure distributions, static airflow trails, and of course all of the graphs you can get from XFoil. Just lookup both on Sourceforge - they're designed specifically for aircraft analysis, so you don't need to deal with a complete CFD package that needs more setup.

Why CFD? Try the discrete Poisson's Equation. (0)

Anonymous Coward | more than 4 years ago | (#32672728)

There is a lot you can do to introduce useful concepts related to CFD without burying them with all the complexities.

Try doing some 1D or 2D heat conduction, diffusion, or potential flow problems (Poisson's Equation).

- It can be done in parallel with some simple lab experiments (reinforce the fact that computational models *should* be modeling actual physical reality)
- It is a great introduction to numerical methods (finite differences, implicit vs. explicit stepping, all needed for CFD).
- It can be done in Excel or another spreadsheet program, or simple programming code.
- The numerical solutions can be compared to analytical solutions (so you can play around with the effect of grid size on accuracy).

I once taught a heat transfer course. In one class, after introducing the finite heat equation, I had the students line up in two rows facing each other (one for the actual calculation, the second for error checking). Using their calculators, I had each student represent a cell in a 1-D transient heat transfer calculation, and they "stepped" through a transient conduction problem. It was a little tedious at first, but when they got the hang of it they started seeing their local temperature changing they got very interested and excited. Then I changed the time step (Fourier number) which caused their explicit solution to go unstable. The class started to see their numbers diverging wildy (yet their numbers were correct as their partner calculated the same number) which caused a lot of uproar and excitement. I then presented an animation of what their solution was supposed to look like. It was a little tedious, and probably a bit slow for university students, but they really got a feel for the numerics. I think it would go down well in a good high school physics class.

here's a tip: (0)

Anonymous Coward | more than 4 years ago | (#32672766)

Ask those 7th graders who discovered a cave on Mars.

I believe they wrote their own CFD code from scratch over one weekend.

Wooden models, water tank, food dye (1)

dbIII (701233) | more than 4 years ago | (#32673430)

With wooden models, a big water tank with flowing water and food dye squirted down a straw they will get a better grasp of fluid flow than you'll get from computational fluid dynamics. It's like having a dirt cheap wind tunnel. Then you have the whiteboard next to it to describe why the fluid flows that way. Much more memorable than pretty pictures on a screen produced by a mathematical black box of equations that they will not be able to understand. I'm not being condescending since that is what has worked at a third year University level.
Keep it visable and never more than two dimensional.

Elmer (1)

govt-serpent (600668) | more than 4 years ago | (#32673866)

Elmer from [] ... free, windows executable available, MPI capable. Geometric model has to be made separately I believe.

explane it to them (0)

Anonymous Coward | more than 4 years ago | (#32675524)

I suggest X-plane. It is free for 10 minutes use. You can design an aeroplane and then fly it in the game.

I am using openflower (0)

Anonymous Coward | more than 4 years ago | (#32678138)

I am using openflower for CFD. I am not a professional aero,hydro,or-other-dynamicist, just an amateur. Openflower ( is capable, though it seems to be limited to models with restrictive symmetry. (Models you start with must be built by extruding a plane model; trying to build one without extrusion, arbitrary placement of walls, all fail; maybe because of my ignorance, but there it is...)
It uses GMSH to build the models and generate the mesh, with a xxx.flw control file to define source, sinks, and impenetrable walls, and other initial conditions. All control files are text files, easily edited with a simple text editor.

There are a bunch (30 or so) examples, that you can modify to meet your own needs; all are basic, simple models, probably very appropriate to students.

I will agree with the respondent who said "NEVER discourage a teacher from trying..." or whatever his exact message. If it fails, so what? There will be one student who says, "Gosh, maybe if I did this, it will work?" And that may lead to a career in aerospace, or other things.

Tutor from Zeus Numerix (1)

achten (1032738) | more than 4 years ago | (#32680376)

The tutor offeering from Zeus Numerix is a good option [] [] This is meant to be an aid for the instructor in teaching fluid dynamics.

You can do this easily with physical models (1)

Danyel (107479) | more than 4 years ago | (#32682428)

You can do this easily with physical models held in place by a stand, colored smoke from smoke bombs or even dry ice, and a fan. What you are looking for is turbulence. Which is easy to spot as the smoke passes the variaous parts of the model. It shows up as swirls.

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