Aerodynamics Tests
 

I know that at least some of you will be interested in this... but some help is NEEDED

Im in the amazingly happy position to announce to you all, that I have access to my university's wind tunnel. Its a bit old, but they got it from Farnborough and it was used to test aircraft models. It has a 3d jig so it can measure drag, lift etc. Nowadays its used to test mmostly smaller pieces up to real size motorbikes.

Im going to build a rig with multiple oriffices for smoke testing (the one that shows multiple lines and how they get altered by the car's body)

Now i would like some info on where i could find a good beetle based lexan cover for an R/C. Probably it won't be a 1303 but i could alter it.

My goal is to madel the whole suspension front and rear along with inner fenders , engine, transmission and axles. I will try to use similar sized wheels and perform an initial test, so i can assess the beetle's stock aerodynamics.

As a next step i would try and modify the cover and model my body kit and run the same tests in order to see how good it is.

Finaly I would like to improve it further more, if time and budget allows.

All smoke testing will be recorded on video and photos.

If all goes as planned, the results of the initial test are going to be posted here for all of us to share.

If a lexan cover can't be found, or the one found isn't that good, I would try to make one from balsa (cheap and easy to scalpture on cnc)

If all of this fails, Im already building a 3d model of my body kit equiped 1303 and will run CFD on it to assess the aerodynamics.

if you have more info or want to help email me on beetle1303@hotmail.com which is my personal email.


Last, but not least, we could simulate side scoop different positions and probably different chin spoilers.

Rob (Judgie), we all seen ur trys to improve ur amazing hill climb race car, and u are in the metal trade and u got skills man, I would be really thrilled if we could work something out

Cheers,

Chris

hey dude that's soo sweet
welLI can help you on the bug body I'm also big into R/C so if you go to

http://www.towerhobbies.com/

I know that they are the biggest in the US and I knwo that the body was made by Tamiya

hope that helps


Chris.

I came up with this

http://www2.towerhobbies.com/cgi-bin...I=TAMC0953&P=X

Its a baja based off road.
Spoke with the UK agents 5 mins ago and they have the shell and glass parts for it specially ordered from Japan. They got it for another guy, so i could get in the middle and buy it in the following working hours, so hurry up guys.

THe better the base model is the better the results will be

Chris

Check this out http://www.germanlook.com/Forums/showthread.php?t=8322 This might be something.

What about a model? I know I have seen better but this is all I could find

http://cgi.ebay.com/REVELL-1964-VW-V...QQcmdZViewItem


Mike

very interested too see what results you get, shame there aint much choise for beetle models, all seem to be standards and not very big. i been looking for a good 1303 shell for a while to make lill version of mine. anyways look forward to reading more

http://www2.towerhobbies.com/cgi-bin...&I=LXPXS5&P=ML

There is a link to the model. Shop around and you might be able to find it lower. Towerhobbies is nice and all, but a little higher than other places.

First update:

Order this
http://cgi.ebay.co.uk/VW-Beetle-body...QQcmdZViewItem

should be here next week:)

Since the cover has the wheel openings closed i can shape the fenders to the original. Along I will try and make a floorpan and the trans, engine, axles and wheels to fit under as in a real beetle.

I will post pics to follow.

For my body kit version i will use either thin pvc sheets so i can shape them, and epoxy to mount them and filler paste to perfect the final model

Im thinking of doing half stock and half modified, and seperate them with a pvc wall running across the centreline of the car.

also i will try to make the roof spoiler (lip) that goes above the rear window

Chris

I am very interested how much lift a beetle creates at high speed (say above 100 mph ++) and how much the roof (lip) spoiler can do to prevent that.

Couldn't you just drive-in a complete 1303 in there? :D That would be só cool! :D

Thanks,
Walter

dont know what i can do to help, but anything i can do just ask. :D
can tell you that the front splitter had more effect on the handerling than the rear wing but the rear wing improves the high speed stabilaty.
cheers rob

from what i have always been told is the lift on a beetle is directly related to air trapped in the fender areas. if you have releif holes or louvers in the back of the fenders it helps in stability of the car at higher speeds. seems logical since it is more directly the shape of a wing. but i may be wrong. just figured i would add what i have heard.

I think that is a very good point !
Now if he could just prove that as well in the windtunnel :rolleyes:

Thanx for the replys guys!!!

bigguy, Ive already considered the relief vents on the wings, i just need to prove the best position and the see the results. The problem is that while the best place for the slots/holes for fender relief might cause too much turbulance on the side of the car. This is for stock shaped fenders... In my high speed version body kit the fenders look more like a 935 k3 porsche

Why not fit a 1303?? i wished the tunnel was that big. A motorbike fits though with rider, so i thought that I could use the right side of a real beetle since length and height are not a problem as is width.

If this works, Judgie, here is where u can help a lot with your skills. maybe fab and try different spoilers... and here is where we could try NACA duct (or any duct) positioning with a different piece of equipment we have that measures relative pressures on surfaces ( the lab i did was based on a NACA aerofoil and we measured 14 positions around it at 5 different angles of attack)

Wally, 100 mph is 160 km/h which is 44.44 m/s. I will start at about 80 km/h (around 22.22 m/s) and check the model's rigidity, and if it all is well, will crank the thing up to 70 m/s (almost 252 km/h - 157.5 mph). I am really interested in high max speed aerodynamics, cos i want to prove that with the correct modifications to the fenders, bonnet and decklid, this kind of speeds is achievable (while NOT altering the centreline profile of the roof and the shape of the roof )

Cheers,

Chris

Chris,

I'd say: Go for it! This sort of thing is really interesting and worthwhile (as in saving lives for us dumb *ss*s that actually try to drive too fast with a 'naked' bug :D )!

Neat Stuff
 

I hope you keep us posted on this project. This is the kind of stuff I find fascinating. Here is something along these lines with a WWII Jeep model!
www.sageaction.com/auto.html
They are using helium bubble generators and strobes to get these photos.