Good News Everyone

[trebuchet03]

On my home computer, I've recently acquired Solidworks and COSMOS Floworks... Which means, I can do CFD modeling at home :thumbup:

Right now I have an HPV fairing under analysis with about 2.5 million cells (which I assume is floworks speak for elements?) - it's on iteration 281, taking a little more than 30 seconds per iteration... and I have no idea when it will stop (I'm told it stops when it converges - so it's done when it's done :p).

Sorry, I just excited because I've been trying to get a hold of this for weeks now. Going into school to use this has been a total downer as I would have to babysit the thing :thumbdown: Now I just set it and forget about it, and I'll get data later :D

[Nerds laugh at me]

Wow. That is great news.

[cfg83]

trebuchet03 -

Oh boy oh boy oh boy oh boy. Where I am going to get a 3D-computer-model of a Saturn SW2?!?!?!?!?!?!??!?!

CarloSW2

[trebuchet03]

trebuchet03 -

Oh boy oh boy oh boy oh boy. Where I am going to get a 3D-computer-model of a Saturn SW2?!?!?!?!?!?!??!?!

CarloSW2

If you can get me a model that solidworks can understand... I'll run the simulation :thumbup: It's not as accurate as Fluent, but you don't have to do any meshing - it's mostly just plug and chug :thumbup:

[cfg83]

trebuchet03 -

If you can get me a model that solidworks can understand... I'll run the simulation :thumbup: It's not as accurate as Fluent, but you don't have to do any meshing - it's mostly just plug and chug :thumbup:

I was half joking because I know that you could end up inundated in requests in no time ... However, I do have an obsolete version of AutoCad lying around. If the output file format/version is compatible, then I could do the modeling. Talk about rust, I haven't touched AutoCad in maybe 15 years.

What was the price range of the software you got?

CarloSW2

[ChrstphrR]

Can I perk up because you've found/made a model of a Mk IV Jetta? :)

I'd be more than willing to contribute CPU time to a(nother) problem if it can be divided up at all.

[trebuchet03]

Can I perk up because you've found/made a model of a Mk IV Jetta? :)

I'd be more than willing to contribute CPU time to a(nother) problem if it can be divided up at all.

No Mk4 (yet) :p I'm not sure if it supports distributive processing - I know I have access to my school's cluster, but I'm not certain if cosmos supports it (fluent, does if I recall).

[Nerds laugh at me]

I do modelling as a hobby.
I don't have Solid Works, but plan to buy it for sure.
I currently own Softimage XSI which is similar to 3DS Max and Maya.
I have ( or had ) a model of a 1993Honda Civic hatchback that I was creating for the purpose of doing CFD tests.
I planned to create several variations and test them on the computer before attempting the real thing.
I recently had a major crash and my computer is dead now ( I'm using my folks computer at the moment)
The hard drive is still good though and I believe the car model is still useable.
I am ( was ) building the model using polygons.
Can I use a standard .obj mesh that is imported into a CFD program to do tests on, or is there some other process that is needed to use a mesh ?

I planned on modelling fine details such as even the wiring and bolts under the chassis using displacement mapping.
Is displacement mapping even usable in a CFD program ?

(From what I have seen CFD software is really hard to aquire. Some of it is even government controlled to keep it out of the hands of 'terrorists'.)
Also,I have never seen an 'Educational version '. The software is usually so expensive that a company rep will visit the place of purchase. Is the version that you are using owned by your school or can students actually purchase it ?
cfg83 : As far as a SW2 model goes, you might try www.turbosquid.com
They have a lot of meshes.
If you can't find one, I might could ....... maybe volunteer to create a simple one whenever I get my computer situation up and running.
Chrstphr : A Mk IV Jetta ? What year would that be ?
I'm considering buying a Jetta TDI myself, so I would be very interested in creating a model and seeing any resuts that could be gained from CFD.

[Nerds laugh at me]

trebutchet03 :
I appologize. I need sleep so I'm really 'spaced out ' out right now.
I notice you have a Jetta - the Mk IV that was spoke of earlier.
This would be the body stye that I too would get.
It is so close to the silouette os a Ford Fusionthat I brought the two together in Photoshop and overlayed them together. They are almost a perfect match.
This excites me because of what was done on the Fusion at Bonneville ( reducing the .Cd down to .22 with a stock appearance )
Not much would have to be done to a Jetta to copy what was done with the Fusion . Just drop it a few inches, slap some disks on it and a wing and voila !

( And don't forget the biodiesel ! ;)

[cfg83]

Nerds laugh at me -

...

cfg83 : As far as a SW2 model goes, you might try www.turbosquid.com
They have a lot of meshes.
If you can't find one, I might could ....... maybe volunteer to create a simple one whenever I get my computer situation up and running.

...

Thanks, I found this one :

Saturn Sedan Compact Car
http://www.turbosquid.com/FullPreview/Index.cfm/ID/272809
1086

It looks like a 3rd Gen body, but that's close enough. Changing it to be a wagon should be easy, just extrude the rear window to the end. I am guessing that it is smooth on the underside.

Is a "3ds max" file format compatible with what COSMOS needs?

CarloSW2

[Nerds laugh at me]

Nerds laugh at me -



Thanks, I found this one :

Saturn Sedan Compact Car
http://www.turbosquid.com/FullPreview/Index.cfm/ID/272809
1086

It looks like a 3rd Gen body, but that's close enough. Changing it to be a wagon should be easy, just extrude the rear window to the end. I am guessing that it is smooth on the underside.

Is a "3ds max" file format compatible with what COSMOS needs?

CarloSW2


Once I get my computer up and running ( or just create a new one ) I'd be happy to modify that model.
Today is the last day of my vacation, so I will be without a computer or internet from now on.
Hopefully I can fix my system soon.

My mother has the same car as you- but the coupe version ( the version that you have a model of. )so I will have plenty of reference to go from.( It is even the same color )

[ZugyNA]

Here is a simple idea to test?

Reverse airfoil vs almost blunt:

"I had a Plymouth Reliant Station Wagon, with a 2.4 L engine and an automatic transmission. We used it to go camping quite a lot, so I built a car top for it, the length of the top and about 20" tall. I built the front to match the angle of the windshield and just squared off the back.

In terms of packing and hauling it worked really well. I had to put air shocks on the car to get it back to level, but after that it worked great.

The only problem was that with the heavy load of people and equipment filling the entire car and car top, I would get up to about 56-58mph and then it would be like a hit a wall. If I had a really long run, I might have been able to get it up to 65mph.

One year, on a annual trip to Death Valley, in December, I wanted to take some fire wood with us, since you can't get any their. However, we were out of room, so I put a tarp on the top of the car top, stacked a pile of wood about 10" high and about 3 ' long, at the back end of the car top.

In previous years I would get about 17-18mpg, with the car top on. My gas mileage went up to about 22mpg. Additionally, when I got up to about 57mph, I didn't seem to hit the wall, like I had previously.

So I got some cardboard and fabricated a shape to put on the top of the car-top/carrier. The shape was a reverse airfoil, upper half, placed across the top of the car-top/carrier. With this shape, I was able to drive at a higher speed, I could pass other car's at 65 and so forth. I also was able to get 22mpg-25mpg.

I gave the car and car top to my parents. They made a trip with it, with 5 full size adult's and with the car packed with everything from the kitchen sink to who know's what. I asked my dad how he thought they had done on mileage and he said he had only checked the first tank of gas, which didn't make any sense, because he was always checking mileage, on trips. He said that on the first tank they got 25 mpg and he was dumbfounded. He said he didn't think anyone could ever get that kind of mileage, with that kind of load, in a car with that size of engine. So'o he quit checking it because he didn't want to try to figure out how it could be getting that, in case it was because of some etheral experience or cause he might jinx or upset the balance of, if he tried to figure it out, to closely.

I believe what was happening is that the huge box shape on the back side was basically creating a huge vacuum behind the car and that the reverse airfoil shape caused the air to be accelerated from the top of the car back down behind the car, breaking up or releasing the vacuum effect's on the car. In either case, their was definitely a force beyond just frontal surface area, which was really dragging the car down, as the speed's went up."

+ 22 to 39 % mpg gain

This wagon has a sloped back end to it...around 70* rather than 90*?

This involves increasing frontal drag substantially but still seeing substantial reduced drag overall.

I'm actually trying to test this idea with a small wagon by using some leaf filled bags, a section of waferbaord and a tarp over it all to try to duplicate this shape partially. Looks like I'm going on a trip. :D