Australian Belly Tank

[Seldom Seen Slim]

"For reasons that don't bear explaining I wasn't sure which way the shift went until yesterday...it works in a cross pattern , you know, like a cross ,not an "H" ."

It's simple -- you're on the other side of the equator and international date line from us, so the shift pattern is of course farkled-up.

That was simple.

[1212FBGS]

slim
what the heck are you talkin' about... don't ya know were talkin' about sailing here and jack is tryin' to talk tha ausi's out of a beer mug they don't even have.... jeeeesh pay attention...

[revolutionary]

I'm a relative newbie to the LSR Tao of car building but I just spent the last hour reading the ongoing saga of your car and have to say I'm duly impressed with your commitment and fortitude.  Guess I'm just used to the drag racing world of GOT-TO-GET-IT-DONE-TONIGHT-SO-I-CAN-RACE-TOMORROW mentality. 

Looks like you're not far away from tying up the loose ends and hitting the salt rolling - assuming there is no 'R' word at Speedweek '08.

[Reverend Hedgash]

Thanks Reverend Lutionary.

I admire your commitment and fortitude to read the whole saga thus far, it sure could do with an edit.

Thanks for your comments.

The DLRA club meeting went well yesterday with someone confessing that they are on the verge of buying a rolling Belly Tank project with a view to getting it up to speed. Top news, looks like there will definitely be a few Belly Tanks next year.

We also talked about running two tracks which will be great if we can it sorted out... for next year. Rod Hadfield and others will be checking out Bonneville this year to get the skinny on how to improve our tin pot affair. All good.

I have to say that I am really enjoying the fabrication side of the tank now. We have passed that hump where all you can see is what it is missing. Now we can just improve, and the simple act of making an aluminium cover to protect the sparkplug leads from the fan of the alternator is extreme satisfaction.

I am just itching to get back into the shed and improve something else...

Reverend H+

[Dr Goggles]

Thanks Revolutionary , it's been an odyssey I can tell you.....neither of us have Auto or engineering businesses , or dependents ( if that makes any sense ) so it's all been out of work hours and we spent every spare cent we had while we were at it .As I've said before the Reverend and I are the kind of blokes who "think" we can do anything and are way too stubborn to concede defeat ...they have been valuable "traits"....if not for them we would have given up .We spent a stupid amount of money and not a single person who sees what we've built says anything  other than "where did all that go?"Anyone who's raced anything and more particularly built a race vehicle knows nothing is cheap but when there's no blueprint for what you're doing and you set some parameters that make it unique , you're really in for it B$G time!!

We haven't been motivated by an urge to beat anyone , there's no-one else in our class(E/GL) here , just a strange fascination with tanks , we still think they are the coolest looking things ever made with four wheels and we wanted to make one ourselves . When we went to the salt for the first time  it sealed the deal...the type of people it attracts are the same both here and there from what I can gather .Inventive . independent people with a drive to achieve something that not too many people "get".....my sign off on our club message board is " Few understand what I'm trying to do but they vastly outnumber those who understand why"

It's been a great experience , just building it .....racing it is going to be a whole new trip again ......lots of gradual steps ...heaps and heaps of learning and arguing over the detail and science of what we're trying to do ....some disappointments , some fights , lots of people staring at it and shaking their heads , others with their eyes glazed over wondering when I'm just going to " shut up about that BLOODY CAR"......I've loved every minute of it.

It's simple -- you're on the other side of the equator and international date line from us, so the shift pattern is of course farkled-up.

....well ,Mils Nees Modles , I did make one concession in order to get it right the shift is on the RHS of the driver which is a blinkin' travesty!!!

........good point Kent , we need to get back on topic and talk about, er , sailing....

[bones]

NICE work Doc&Rev.
Now it's running right you can take it for a quick spin round the block(does it have enough steering lock?)
Ev & I go to Heathcoate for the drags, I would like to have a look if we down that way.
cheers Bones

[Reverend Hedgash]

Thanks Bones,

Yep good idea. I think Heathcote would be the perfect place to check some stuff out. Be a month or two yet but we'll definitley let you know when we go.

rH+

[whitworthsocket]

Hello Doc & Rev,
Like your work Quite a few posts ago you mentioned a 3d Cad package. Can you name the product and state the pro's and con's?
I'm using AutoCAD and I can work very well in 2D. But 3D looks a learning curve I don't have the time for.
Regards Whitworthsocket.

[Dr Goggles]

Hello Doc & Rev,
Like your work Quite a few posts ago you mentioned a 3d Cad package. Can you name the product and state the pro's and con's?
I'm using AutoCAD and I can work very well in 2D. But 3D looks a learning curve I don't have the time for.
Regards Whitworthsocket.

hmmmmmm ,I see a fruitful and possibly fruity relationship here ....a guy who calls himself Whitworthsocket and another one who wants to buy a Morris Minor panel-van...talkin' 3D ....

Watching the Reverend work in 3D has been a thing to behold Whitworth' , at one point I said to him, long before we laid the first weld..."it'd be great to know what we'll be able to see from the drivers seat ...if we can see the tops of the front tyres..." , "hang on a moment " he said....and promptly put the view point in the top of the drivers compartment like , you know , where your head would be and hey presto!!! there it was.........when we first laid the body panels onto the frame I was shaking my head saying incredulously " it looks just like the drawings"......the Reverend was looking at me a little offended " um , what did you expect it to look like"?

All that said it seems that looking back one of the most critical points in this whole process is the when you're sitting on a table with a helmet on going brmm, brmm with the other guy measuring around you ,in the long design process that follows this seemingly embarrassing part figures get rounded and little errors get compounded and the danger is that that the all important bit about the driver fitting in gets a little forgotten about .When you are trying to fit a lot into a little space room tends to disappear rather than seemingly come from no-where .I'm sure in the future we'll manage to wring some room out of it but right now it's tight all over .It seemed despite the amount of time that went into drafting that it still acted more as back-up than the last word because at every turn we discovered conflicts of space or measurement that required on the spot changes , then back to the CAD to reassess and redesign.The old addage "measure twice , cut once" is sound indeed , when building a tank i'd consider measuring twenty times and still expecting to cut twice..........................before you chuck the part out and make a better one.

[Reverend Hedgash]

Hello Mr Socket.

AutoCad itself has a quite a good 3D package these days and given that is a program that you already are aware of, I'd recommend exploring that feature of it first.

The help files in it give fairly good synopsis of how to build objects, shade them and print them. Else there are a lot of free tutorials on the web.

If it is cool renders that you want you can then export these drawings to any one of a number of 3D drawing Rendering packages to develop them into a decent picture, for example 3DStudioMax (3DMax), Rhino, and Maya.

I typically draw elements of the car in AutoCad then import them into 3DMax

3DSMax  is a program with all the bells and whistles, although this makes it harder to master in the long run than some of the simpler rendering packages out there it really produces good results and has a huge following and therefore support on the web. You can complete generate the 3d elements in the program, colour them, add lighting, even animate them into movies.

A quick search for some car specific tutorials for 3DMax brought up the following examples:

http://www.carbodydesign.com/tutorials/software-tutorials.php?app=3DStudio%20MAX
http://www.danielbuck.net/index.php?page=tutorials
http://www.3d-palace.com/tmas/video.php?vid=58

It does take time, this is no quick fix to get super results, but you should be able to get something serviceable in reasonable time.

As Dr Goggles mentioned, one of the best aspects of the tool is the ability to move a viewpoint around the object that you are looking at so you can really get a feel for its shape. This is so handy when blocking out a car where you can quickly alter wheelbase, colour, shape, etc.

I must mention that I have an industry bias to these programs as I am a puppet animator and architect by trade and so these are the design tools I use regularly.

Other programs from different fields that you might be looking at would include something like SolidWorks which is from the engineering direction and can help set up all the CadCam tooling for you for the parts you wish to manufacture.

What do you want the program for? Pretty pictures or to work stuff out, or to actually build it with?

Hope this has been of help.

rH+
speed deacon

[whitworthsocket]

Thanks for the info, I will be  using the software to design and build the machine and the wind tunnel.
I have Rhino but again the learning curve/time is all time spent away from fabrication.
Regards Whitworthsocket

[Reverend Hedgash]

Building a virtual wind tunnel hey?

I have read a bit about the growing ability of software to predict real world conditions for aero design. Would love to hear and learn more if you are into it. Maybe we could set up a new topic for it?

rH+

[whitworthsocket]

Steady On, Im talking about a real wind tunnel.
My only experience of a virtual tunnel is reading the JCB Dieselmax site

http://www.jcbdieselmax.com/html/car.php?PHPSESSID=dfbda02db0fbb0e9fa168c4dd8224347

http://www.jcbdieselmax.com/html/car.php?subsection=3


I quote directly from there.
A record-breaker's body shape not only needs to be highly aerodynamically efficient but the underside of the vehicle is also of critical importance, because the air flowing under the car accounts for about a half of the total aerodynamic drag.

Ron Ayers believes that the interaction between tyre and salt can significantly affect the aerodynamic efficiency; the effect of salt and debris thrown up by the cars passage slows the car down. To minimise this drag he has very carefully shaped not just the spats around the lower section of the wheels, but also the flow of air through the choke points between the wheels. Spray beneath the front of the car is deflected out by the sides of it behind the front wheels, to ensure that the rear wheels and tyres run on as clean a surface as possible.

All of the aerodynamics study was done using computational fluid dynamics, not in a wind tunnel, for two reasons.
JCB DIESELMAX JCB DIESELMAX

"Even at the speeds we envisage, Ayers explained, compressibility effects are beginning to become significant. Indeed, in the region near the wheel/ground contact points the local airflow actually goes supersonic! We could not simulate such effects in a low-speed wind tunnel with a rolling road.

The second reason is one of scale. To fit our long slender vehicle into a tunnel with a rolling road would mean restricting ourselves to a model scale of about one sixth and the errors would have been too great.

The main changes as the shape evolved were to lengthen the nose and round it off, to lengthen the tail and minimise the frontal area. At every stage Ayers had to achieve the optimal balance between aerodynamic drag, skin drag (the larger the surface area the higher the skin drag) and downforce. If the car is envisaged as an arrow or a dart, it is the tail fin that acts as the flights to maintain stability at maximum speed."

Regards Whitworthsocket.

[whitworthsocket]

To all interested,
Here is the results of my wind tunnel research. There are many references to the wright brothers windtunnel I have not included them.


http://www.geversaircraft.com/wt/wtsmall.htm

http://mae.uccs.edu/jroney/SpaceGrant/WTReport.pdf

http://archives.caltech.edu/search_catalog.cfm?results_file=Detail_View&recsPerPage=1&firstRecToShow=36&search_field=Wind%20tunnels&entry_type=&photo_id=&cat_series=

http://www.speedace.info/wind_tunnel.htm          http://www.speedace.info/pitot_tube.htm

http://www.grc.nasa.gov/WWW/K-12/WindTunnel/wandering_windtunnel.htm

http://www.ezcomm.com/Windtunnel/index.html

http://www.windtunnels.arc.nasa.gov/pics/9x7/9x7dimPlan.html

http://www.theplanpage.com/Months/2306/tunnel_files/tunnel.pdf

http://www.galcit.caltech.edu/awt/index.html       http://www.galcit.caltech.edu/awt/tenfoot/wirerig1.jpg

http://lisar.larc.nasa.gov/IMAGES/SMALL/EL-1999-00415.jpeg

http://www.nlr.nl/documents/flyers/f137-02.pdf

http://www.lboro.ac.uk/departments/tt/research/aerodynamics/wind-tunnel/tunnel.html

http://connect.larc.nasa.gov/connect_bak/pdf/measure.tools.guides.pdf

This is what I have come up with I like the Gevers aircraft for a straight through.
I am still not sure if I have room for one of those So it may be a bigger version of the
Speedace.

If any one has any more I would appreciate the links.
Regards Whitworthsocket

[whitworthsocket]

Reverend Gash and other wind tunnellers,
I happened on this after I had posted the first info about JCB Dieselmax

http://www.autobloggreen.com/2006/09/14/aerodynamic-jcb-dieselmax-broke-land-speed-record-without-wind-t/

Quote
"
A few weeks ago, the JCB Dieselmax broke the world land-speed record for a diesel-powered car. For good reason, the posts we wrote on the subject (see below) were quite popular, so I know there's going to be at least some interest in the technical news that the Dieselmax was built using Ansys Technology. Ansys has been making simulation software since 1970, and the Dieselmax's aerodynamic style was designed using the company's Fluent computational fluid dynamics (CFD) software package without any additional wind tunnel testing. One reason was that the Dieselmax is too long for traditional wind tunnels. From a green perspective, using a computer instead of a wind tunnel seems like a good way to save energy, and the results sure speak for themselves."

I also had a look at
http://www.ansys.com/products/cfx.asp

There may be enough to start a new thread as the Rev suggested.
Regards Whitworthsocket