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Wind tunnel software for fun and profit$$$$


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#1 Greg Locock

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Posted 29 November 2011 - 03:57

http://autodeskmfg.t...deks-alias.html

Looks fun

http://www.microcfd.com/download.htm

I used some old version of this it was lovely, if slow.

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#2 cheapracer

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Posted 30 November 2011 - 12:50

I did download the MS one Greg, will try when get a chance - thanks.

#3 MatsNorway

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Posted 01 December 2011 - 19:36

Greg i believe i sendt you a PM.

I will try the inventor add on if i can find the trial version. (assuming it is one)

#4 Greg Locock

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Posted 01 December 2011 - 22:53

Greg i believe i sendt you a PM.

I will try the inventor add on if i can find the trial version. (assuming it is one)

No PM, and just as well, I'm at 99%

#5 MatsNorway

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Posted 02 December 2011 - 19:37

My bad it was that..grunt..guy..

#6 MatsNorway

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Posted 06 December 2011 - 15:15

Testing out falcon now.. its actually very impressive once you get the hang of it.

You can make any shape you like in Inventor, convert it to a STL file and falcon will eat it.

i will se if i can get a video up.

Edited by MatsNorway, 07 December 2011 - 16:41.


#7 MatsNorway

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Posted 06 December 2011 - 15:39

Testing out falcon now.. its actually very impressive once you get the hang of it.

You can make any shape you like in Inventor convert it to a STL file and falcon will eat it.

i will se if i can get a video up.




#8 MatsNorway

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Posted 06 December 2011 - 21:23

Small, low quality video.


First impression is that it has issues with "hanging" on to surfaces.

The 2D system gave some odd looking pressures over a wing i made. ill get back to that.

#9 MatsNorway

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Posted 07 December 2011 - 16:33

Thank you Greg this was awesome. I think i can use this for projects.

Cheapy do you have a model of your car on CAD?

Edited by MatsNorway, 07 December 2011 - 16:37.


#10 cheapracer

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Posted 07 December 2011 - 17:20

Cheapy do you have a model of your car on CAD?


Indeed I do and would be very grateful to see it in flow, give me a day or two to get it.

It's in Solid Edge, what formats for Mats?


#11 MatsNorway

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Posted 07 December 2011 - 20:44

Indeed I do and would be very grateful to see it in flow, give me a day or two to get it.

It's in Solid Edge, what formats for Mats?


STL only for Falcon. But if thats unavailable i can go through Inventor or some other program at work and convert it.

Inventor can convert to a lot of different types. Some it can`t even read when converted. STL is one of them. that makes it a tiny bit of a hasle. as i have to go into a inventor file and make a new versjon when i want to test something new...

i will make the full list of file types tomorrow. if STL is not an option.

i made some beautiful runs with a rc car like chape. one with a small diffuser the other one with a flatt bottom. Falcon even produced vortexes.

the lines that simulate airflow is not allways good to look at. the pressure map is better. But thats only 2D. But in total im very impressed. the program is also very stable, no crashes.

I was supposed to upload the pictures here today but i forgot to take the memory stick out before i left.

Edited by MatsNorway, 07 December 2011 - 20:47.


#12 MatsNorway

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Posted 08 December 2011 - 07:20

Catia V5
pro/engineer Granite files

STEP
SAT
Parasolid text files
Parasolid binary files
STP

Edited by MatsNorway, 08 December 2011 - 07:21.


#13 MatsNorway

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Posted 08 December 2011 - 07:32

Flat bottom vs Diffuser.

Section view of a 1/12 scale type car. Size is a bit of.
Posted Image

you can`t do much with the car in the tunnel program so i had to slice the model in half and adjust how wide the "paper strips" where. as you can se there is some of the "strips" of paper that goes on the outside.


The difference is way bigger than i expected.

Due to the big surface area at the back this would probably generate a lot of drag.

A bit of a unexpected side effect of the diffuser is that it seem to remove some of the pressure over the front. it might just be that instead of getting pressured down it get sucked down.

The Color map might be a bit of because of the section view being too close to the endplates. (read: the two pictures is not from the same section)

Just something i made in a hurry.

Edited by MatsNorway, 08 December 2011 - 07:36.


#14 cheapracer

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Posted 08 December 2011 - 11:06

Thanks Mats, maybe tomorrow as I also forgot my USB today.

#15 cheapracer

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Posted 08 December 2011 - 11:08

Flat bottom vs Diffuser.

Section view of a 1/12 scale type car. Size is a bit of.
Posted Image


Mats, try a front splitter of varying lengths out the front of that ....


#16 MatsNorway

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Posted 08 December 2011 - 12:59

Mats, try a front splitter of varying lengths out the front of that ....


Will test splitters tomorrow. I also got a complete RC chassie i can test out. Just need to make a body for it.
Been mostly fidling with delta wings today. Ideas to rc planes and stall speeds.

Edited by MatsNorway, 08 December 2011 - 13:01.


#17 desmo

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Posted 09 December 2011 - 02:03

It looks like the non-diffuser model would have significantly lower drag based on the low pressure area behind the body of the diffuser model.

#18 Tony Matthews

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Posted 09 December 2011 - 08:25

I haven't seen any posts from cheapy for the last coupla days - do you think he's ignoring us?

#19 cheapracer

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Posted 09 December 2011 - 09:04

Posted Image

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#20 MatsNorway

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Posted 09 December 2011 - 09:07

It looks like the non-diffuser model would have significantly lower drag based on the low pressure area behind the body of the diffuser model.


Yes and no. There is less pressure on the front and in the dip before the spoiler ish shape. is it enought to compensate? i think not. But drag is not the goal. Downforce is.. unless you are in a underpowered veichle.
I forgot to mention that the program gives the Cd value (coefficient of drag?) ¨

I will rerun the models and repost the results.

#21 desmo

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Posted 09 December 2011 - 23:04

Sgt. Schultz should be CFDed. He's definitely a low speed bluff body in ground effect.

Who am I kidding, we all are.

#22 MatsNorway

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Posted 10 December 2011 - 11:35

Desmo.. Is there any chance this forum gets to upload its own pictures/files?

It would raise the quality of the forum substansially

#23 desmo

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Posted 10 December 2011 - 23:32

It'd be cool but no. It's pretty easy, or should be, to post images here using one of the many image hosting sites dedicated to that.

#24 MatsNorway

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Posted 11 December 2011 - 09:47

It'd be cool but no. It's pretty easy, or should be, to post images here using one of the many image hosting sites dedicated to that.


Yes it is. But thats not quality.. quality lasts. Imageshack pics die after s short time. making old threads useless. Might just as well be a auto delete on some of them.

#25 Catalina Park

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Posted 11 December 2011 - 10:18

Yes it is. But thats not quality.. quality lasts. Imageshack pics die after s short time. making old threads useless. Might just as well be a auto delete on some of them.

Use a good photo hosting site and don't use imageshack.


#26 TURU

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Posted 11 December 2011 - 10:22

Yes it is. But thats not quality.. quality lasts. Imageshack pics die after s short time. making old threads useless. Might just as well be a auto delete on some of them.

One can always setup his own server and not worry about anything.  ;)
BB servers would be down after one week if they allowed uploading pictures to them.

#27 MatsNorway

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Posted 11 December 2011 - 11:17

One can always setup his own server and not worry about anything. ;)
BB servers would be down after one week if they allowed uploading pictures to them.



1.But you don`t know that before you try it.
2.Sounds like crappy servers..
3.Could limit it to only say nostalgia and technical. or just one of them.



#28 TURU

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Posted 11 December 2011 - 12:21

2.Sounds like crappy servers..
3.Could limit it to only say nostalgia and technical. or just one of them.


2. They don't necessarily have to be crappy for that to happen. (though they seem to be just a tiny, tiny bit crappy :p )
3. I was thinking along those lines too, but am not sure if that's possible. Technically it sure is, but I can't see them doing it.

Edited by TURU, 11 December 2011 - 12:21.


#29 cheapracer

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Posted 11 December 2011 - 13:24

Use a good photo hosting site and don't use imageshack.


Of them all I find Photobucket the fastest, easiest and I've had some shots up for a long time, one lot I even forgot about and logged in/opened them over 3 years later no problems.

Mats, I want to see the results with the splitter added ....

Edited by cheapracer, 11 December 2011 - 13:25.


#30 MatsNorway

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Posted 11 December 2011 - 14:26

Of them all I find Photobucket the fastest, easiest and I've had some shots up for a long time, one lot I even forgot about and logged in/opened them over 3 years later no problems.

Mats, I want to see the results with the splitter added ....


Monday... i got a Word document. i will se if i can get some pics up too. i also did some test related to RC cars for another guy. once again i got slightly surpricing results. But they all made sence.

#31 cheapracer

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Posted 11 December 2011 - 16:32

Monday... i got a Word document. i will se if i can get some pics up too. i also did some test related to RC cars for another guy. once again i got slightly surpricing results. But they all made sence.


I asked the guy at work to send me my 3D but it's 103 meg - I'll talk to him tomorrow to trim it down ....


#32 MatsNorway

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Posted 11 December 2011 - 19:42

oww. well thats a issue. send piece by piece? :D

#33 kikiturbo2

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Posted 11 December 2011 - 20:02

I asked the guy at work to send me my 3D but it's 103 meg - I'll talk to him tomorrow to trim it down ....



use dropbox or some similar file hosting utility..


+1 for the photobucket BTW...

#34 desmo

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Posted 11 December 2011 - 23:12

Get your own domain, it's cheap and many have essentially unlimited server space allowed. Everyone should have a personal domain totally under your own control. It's massively better than relying on a third party image hosting service where you don't have ultimate control.

#35 Canuck

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Posted 11 December 2011 - 23:42

Agreed

#36 cheapracer

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Posted 12 December 2011 - 07:48

oww. well thats a issue. send piece by piece? :D


China's got hundreds of unlimited server space and it was already on one of them, my meaning was about the general size of it to be handled by Mats.

By the way everyone here has unlimited internet, mine is ADSL, not rocket speed but quite fast and $120 per year.

#37 munks

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Posted 12 December 2011 - 14:34

By the way everyone here has unlimited internet, mine is ADSL, not rocket speed but quite fast and $120 per year.


Nice! BTW, are you saying that everyone gets *free* unlimited internet, and you are simply paying for a higher speed?

#38 MatsNorway

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Posted 12 December 2011 - 14:43

China's got hundreds of unlimited server space and it was already on one of them, my meaning was about the general size of it to be handled by Mats.

By the way everyone here has unlimited internet, mine is ADSL, not rocket speed but quite fast and $120 per year.


I thought you had issues sending it pr email.

Alternative:
Its not a issue to download big files if you have a hot link pr pm.
I have recieved videos on machines that way.

Not sure about the limitations pr outlook.

Just try mail first. the one im registered on is my hotmail account. i think i can get bigger files pr outlook. just try.

Edited by MatsNorway, 12 December 2011 - 14:56.


#39 cheapracer

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Posted 12 December 2011 - 15:00

Nice! BTW, are you saying that everyone gets *free* unlimited internet, and you are simply paying for a higher speed?


Everyone has unlimited, yes you can pay for speed variations, I upgraded from $80 last year to $120 this year for a faster package.

Mats, will have a link for you tomorrow, thanks.


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#40 MatsNorway

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Posted 13 December 2011 - 15:40

Cool stuff. i can`t wait :)

Good news.

I just figured out how to make the program do finer calculations. Its now working and has done so for 20min. Going to leave it on to tomorrow :)

I also found out that i can adjust the groundplane, or so it seems. Thats handy regarding ground effects. who i have had doubts about that this program is good enough for. Mostly due to this being a static simulation and i need the ground to be moving. But no friction from ground plane basically does the same i think.


Every figure i have tested up until today was allways elevated from the ground a little bit. tried to fool it and all but with constant failure.

Edited by MatsNorway, 13 December 2011 - 15:41.


#41 MatsNorway

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Posted 13 December 2011 - 21:45

prior to my discoveries i made a simple diffuser like shape. i was intending to show the differences between something like a rc body and a propper diffuser.

i think i need to go back to simple screenshots. I now go photobucket so that should be no problem.

Here is simple video of the diffuser.

60km`t i think it was.


#42 Greg Locock

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Posted 13 December 2011 - 22:37

I also found out that i can adjust the groundplane, or so it seems. Thats handy regarding ground effects. who i have had doubts about that this program is good enough for. Mostly due to this being a static simulation and i need the ground to be moving. But no friction from ground plane basically does the same i think.

A zero friction groundplane sounds like a good representation of a moving groundplane. The other trick used in real windtunnels is to use a mirror image of your car underneath, and no groundplane.

Edited by Greg Locock, 14 December 2011 - 09:42.


#43 harrypitts

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Posted 14 December 2011 - 13:19

What turbulunce model are you using?

mesh y+ value?

#44 MatsNorway

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Posted 14 December 2011 - 15:28

What turbulunce model are you using?

mesh y+ value?


I don´t think i can adjust anything related to how it figures out the aero stuff.

But its probably a mesh system yes. I will try to get a picture up if anyone wants it.

Mesh y?

only in one axis you mean? it does 3D. :)

(im guessing what you are asking)

+ value?

no idea...


#45 harrypitts

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Posted 14 December 2011 - 16:33

I don´t think i can adjust anything related to how it figures out the aero stuff.

But its probably a mesh system yes. I will try to get a picture up if anyone wants it.

Mesh y?

only in one axis you mean? it does 3D. :)

(im guessing what you are asking)

+ value?

no idea...


Hmm strange that you can't adjust, never mind then.

Looks cool though.

#46 MatsNorway

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Posted 14 December 2011 - 19:36

Hmm strange that you can't adjust, never mind then.

Looks cool though.


Its not uncommon for autodesk to simplify things a little bit. Inventor does not calculate in the chance in the length when something bends. To inventor the part is allways straigth.

Multiphysics got this however. As soon as one of the competitors adds this inventor will probably follow. they are milking the marked and controlling things in a orderly fasion.

Edited by MatsNorway, 14 December 2011 - 19:36.


#47 MatsNorway

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Posted 15 December 2011 - 14:57

Rough and fine mesh. Can you spot the practical differences?

Posted ImagePosted Image

#48 GX390

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Posted 15 December 2011 - 20:03

Thanks for this :)

#49 MatsNorway

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Posted 21 December 2011 - 13:05

I was hoping for some CAD drawings Cheapy. Got a few free hours up to chrismas

#50 cheapracer

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Posted 21 December 2011 - 16:40

I was hoping for some CAD drawings Cheapy. Got a few free hours up to chrismas


Ok mate, I'll do something, I now have .obj file (Autocad) and Solid Edge files, which is preferable?