Testing Aerodynamics Through Software - Page 2 - Fuel Economy, Hypermiling, EcoModding News and Forum

Sven7 · 07-09-2012, 11:36 AM

Quote:

Originally Posted by Shortie771

I have used this with 3 vehicles today. A Honda Del Sol, Ford Explorer and a Jeep Cherokee. Well, I have only been using this for about 2 days, with no experience. Stitching is a new term to me, but I think I know what your talking about. All I have done is downloaded somebody else's model and exported it using the plugin as a .stl. I have done no stitching, but maybe I have just been lucky. The plugin I mentioned might do the stitching when you export the file, if that is even possible.

Ok, because I would definitely be testing an original design in there. Usually you have to do at least some stitching manually.

Too bad about the trial. I'll guess it's over $700 to purchase.

Shortie771 · 07-09-2012, 12:12 PM

I'm still not positive that it is a free trial (fingers crossed). if anybody knows 100% that it is a free trial, please post it and how long the trial it. Worst case scenario, it is a trial so if you want to do anything... Do it fast!

Another thought on the trial. You may be able to get another trial using an alternate email address.

Cd · 07-09-2012, 02:28 PM

I talked to an Autodesk guy that is in their simulation department.
He says the software is meant to test the user demand for a 'basic' version of CFD software.
The software is not meant for doing precise CFD, since it does not use an advanced solver ( not sure about that wording there. )
He says if the software is released, to expect the price to be upwards of 15 K ( fifteen thousand dollars )

Cd · 07-09-2012, 03:11 PM

AUGUST 31 is the kill date on the software .

The software will fail to operate on that date, so everyone download and use this before August !

Source : Autodesk Labs Utilities Project Falcon

t vago · 07-09-2012, 04:55 PM

$15K?!?!?! Wow.

I will definitely get my aero testing done prior to 31 August. Thanks for the heads-up!

Cd · 07-09-2012, 05:04 PM

( That's literally half the cost of the pro stuff : $ 35,000 + ! )

BTW, while looking for a "source" of proof for that last statement , I stumbled upon this quite affordable CFD software ! : http://www.symscape.com/products

aerohead · 07-09-2012, 06:17 PM

In the 'Another Candy Store' thread ,the 'Report' makes mention of the CFD programs offered to the university teams free of charge from Electronic Data Systems.
The only requirement was that the team's car be represented in mathematical form.
The George Washington University team worked a super-computer for long days over two months to refine their racer's body.
The car was broken down into 8,000 separate panels if I remember correctly.I think that this is the sort of software needed to approach reasonable guestimations for 3-D flow.
For a comprehensive discussion on the mathematics of ellaborate 3-D CFD you'll want to study the Japanese Society of Automotive Engineers paper of the 1996 HONDA Dream solar car.It can be found online.

ConnClark · 07-10-2012, 02:00 PM

Having read the description and the performance that they are advertising I can conclude that they are not using a real solver code or that they are using a minimal mesh. Either way the results will not be trust worthy, but it is still light years ahead of flow illustrator. This is an excellent learning tool to learn the basics of CFD.

Right now with openFoam my 4GB laptop takes longer than 3 days to mesh my car model of my Mercedes 300SD. In doing so it uses more than 12GB of swap space (note I have this space as 3 swap partitions on three separate drives and hacked my kernel to improve performance). For simulation time I'm looking at about a week or maybe 2 weeks and even then I'm not going to get the degree of accuracy I want to investigate vortex generators. More ram would help but my machine is maxed.

A serious effort would probably require 4 machines with at least 8GB of ram each and connected with 1Gb ethernet or better.

Shortie771 · 07-10-2012, 02:19 PM

Is openfoam another cfd tester? Hard to believe it takes that long, that's insane. Is openfoam just that much more critical and precise? Because project Falcon only takes a minute or 2 to render my 3D model

ConnClark · 07-10-2012, 06:48 PM

OpenFOAM is a package that can do CFD but it can also do more. Its free and some people actually use it in industry. It is Unix/linux based.

OpenFOAM will do as thorough of a job as you tell it to do.

Note: I just found an error in my 3d model that might explain some of the problems I was having with things taking forever.