Group Purchase of Aerodynamic Modeling Program

[chuckm]

Alibre is a pretty good package that is MUCH cheaper than Solidworks.

One major upside to Alibre is that it readily saves in ACIS format. Doing some research, Gambit can make meshes from ACIS files. OpenFOAM can convert Gambit meshes for its own use.

[RobertSmalls]

I have access to Solidworks, and I'm not terrible at making 3D models with it. I also fired up SolidWorks FlowWorks Express, which is totally inadequate to my EcoModding needs. FlowWorks Express makes attractive (but very low detail) visualizations of flow, but it's incapable of a quantative comparison of one model vs. another.

I think ChuckM has the right idea: CAD software to make a 3D model, export to OpenFOAM for analysis.

[windrider919]

Looking at openFOAM it appears to be a strong program. Instead of trying to run MS and Linux on the same drive I think I would use a second, dedicated drive for the Linux / openFOAM.

As Per licensing, We would have it on one machine, run by one person who would be loading and running other peoples files. So legally there would only be one license. Putting it on the network would make them {Ape > Banana = Big Pile of..... AS} so that would be a big NO.

The vehicle model library would not need to be licensed I would think. Just as each 1st person created it he would make it available to the other owners of brand X.

So you would go to the list and just click on your car to download your particular 3d model.

Geo Metro
Scion
Accord
Camry
Protege
Megane
Jetta
Elantra
F150
Silverado
Previa
etc..................

Example , How many downloads of the Metro would there be? Lots I bet! And as test runs were done the most efficient car would evolve.

[RobertSmalls]

I would love to see some collaboration to conduct CFD analysis of ecomodded cars, thus definitively answering questions about how many MPG rear wheel skirts would give, and comparing the relative effectiveness of several proposed grille block designs, for example.

This collaboration does not require money. As you said, if we create a model, it is our property, and we could share it here under a Creative Commons license. OpenFOAM is Free, so no money there. For CAD software, any software that can handle .DXF (drawing exchange format) is fine. If you're rich, buy a copy of a professional CAD suite. If you're a student or an engineer, use your employer's/school's copy. If none of these apply to you, get free CAD, such as this one that was on the first page of Google:

GSI: CAD X11 Features

[jamesqf]

Originally Posted by windrider919

As Per licensing, We would have it on one machine, run by one person who would be loading and running other peoples files.

The problem with that might be the compute time. As I said, it's not really my field so I can't say for sure, but you might be looking at days/weeks of number-crunching to do an analysis of one model on a typical PC.

[RobertSmalls]

The amount of computation required depends on how detailed of a simulation you need to run. Higher resolution and smaller time step mean more accuracy, but there's rapidly diminishing marginal returns on that. My best guess is it would take hours, rather than days or minutes.

[ChrstphrR]

I'm moving my home, after a bit of an absence. Thank you all for bouncing ideas around for this.

As mentioned months and months ago in another thread on here about OpenFOAM, I was intending to build myself up a linux server at home so I could try and toy with some of the freely available software, like OpenFOAM (it is, by the way, a total pain in the butt to set up!)

Since I'm moving said server half way across Canada, I can't promise either resources, or results anytime soon. But, I am prepared to put in a bit of elbow grease, and try to keep notes on my absent minded explorations once I set up house again, so I can do so.

----

My exposure and dealings with installing, let alone using OpenFOAM make me think of this analogy:

Having coal, sand, iron ore, and a furnace aren't the same as having a steel fender for my car.

That it's a big leap between the two for me, and most people, but I'm sure there's a few people on the planet that could make their own blast furnace and then blacksmith a workable fender, instead of buying one ready to paint.

But, I think I'd be closer to being in that smaller group of people who'd make the fender, IF I were privy to the knowledge and felt comfortable with the steps to do so.

The same goes with OpenFOAM. I've seen end results displayed that show it would do what most of us want. I'm not so sure at this point that I can acquire the knowledge to do so, yet. Everyone that's good at it, is focussing their knowledge on using the program, not building up documentation for newbie end users, at least!

----

What this idea needs is a lot more doing, and a lot less pontificating (a.k.a. immitating "The Thinker" statue), and reporting back on successes and failures, while we fumble about with

• Setting up a server at home, so others can repeat your progress
• How to's on installing some of the free or close-to-free software available for CAD, model manipulation, airflow simulation
• Documenting our exploration into how the different available programs work, so that we figure out which ones are "best" for us to try and use, and/or modify
• Gathering resources (sites, article/book bibliographies, pre-existing HowTo's) so that there's less re-inventing the wheel

Maybe a sub-forum off of the Aerodynamics forum is needed in this case, to help persue this?

Either that, or say, people of like minds here can dig about, identify an existing forum for this, and we invade our little corner of it, to further our "I'm an amateur that wants to model my car in a computerized wind tunnel" agenda.

Right now, all our pokes about are too incoherent, unfocussed, and not collaborative enough so that any one of us can make reasonable progress. We can change that; we just have to put our minds to it.