Round bottom versus flat bottom aero

[jdincau]

Pork Pie;
     Where did you  get the information that the goldenrod was unstable over 425?
Jim

[PorkPie]

Pork Pie;
     Where did you  get the information that the goldenrod was unstable over 425?
Jim

Witness, team member, film material and computer simulation in a (computer) wind tunnel.

Friends of mine checked this in his free time for me, after I watched the film material and asked a bunch of people about this what I saw.

At full speed the car was with the frontend up the ground, on some views of the film sequenzes I got, you can see this very clear - if you got the right film material to watch.

By the way, unstable is the wrong word - it went very well straight for this speed - but he was lifting on the front.........

[Richard Thomason]

Are you sure that was not with the pollywog? I know from talking to both Bob and Bill, that the front wheel drive car was lifting and heading in any and all directions, but never heard a word about the big car being unstable. I'll give Bill a call and see what he says. Anyone else have input to this?

[John Burk]

Polywog had 3" or more scrub radius . I'm pretty shure that was the cause of it's handling problems . The drive line was a copy of Jim Colberts front wheel drive roadster . Does anybody remember how that handled ?

[Richard Thomason]

Wow! I know from persomal experience how that works, or should I say doesn't work

[PorkPie]

Are you sure that was not with the pollywog? I know from talking to both Bob and Bill, that the front wheel drive car was lifting and heading in any and all directions, but never heard a word about the big car being unstable. I'll give Bill a call and see what he says. Anyone else have input to this?

No, I mean not the Pollywog.

Also, I didn't wrote that the car was unstable, he went very good straight.

What the car done, he lift the nose by highspeed, they faster he went he lift more.
Some of the lift was coming from the bigger diameter of the tires, but the front lift more than the rear.

You can't see this not right on the official movie film, but on a other tape which I got a chance to watch.

When I talked with Bill about it, he said that could be possible, Bob was very busy to keep the car going due to the very bad salt condition and he was never sure what cause this problem really.

A good friend of mine, who was with the Summers Brothers at the salt, was a very expierenced witness.
he confirmed that what I saw on the movie, also that from the view on the official tape this lifting was not so visible.

More interested is, that the computer simulation shows the same reaction as it was in reality.

If you ask now, where I got the measurements. This friend has a complete set of blue prints with the measurements.

The Golden Rod is may be very similar as the Thrust II from Richard Noble - the 1983 car. Data's taken during the run and later computer simulation showed, that if the car went on his last run 5 km/h (3 mph) faster, he has flipped.
But the car was absolute stable in the straight direction.

Walking on the borderline..............

[Richard Thomason]

Bob told me that the polywog was speed limited by the fact that it was front wheel drive and the front was lifting and the tires would spin. The tach showed him that. So both cars had severe lift under the nose?

[Harold Bettes]

Gentlemen,

Kindly note that the Goldenrod went at least 425mph on junk salt and not even in high gear! Also note that there were two noses built. I do not agree with the lift comments and about the 3 more mph being closer to the precipice of disaster. The aero testing on the scale model was done at Cal Tech by my kin, W. H. Bettes. There were many unique features of the aero design that are not being addressed in this forum.

Also kindly remember that most computer simulations rely on many assumptions and conclusions before the process of analysis. Such is the current buzz on the use of CFD in solving (tounge in cheek) flow problems.

I could say more, but will relax for a while and enjoy the high country snow.

My regards to all,
HB2

[Richard Thomason]

Harold, I think you've got it right. Goldenrod was good, Polywog was a definate problem. Bob was a consumate driver on the salt.

[PorkPie]

Gentlemen,

Kindly note that the Goldenrod went at least 425mph on junk salt and not even in high gear! Also note that there were two noses built. I do not agree with the lift comments and about the 3 more mph being closer to the precipice of disaster. The aero testing on the scale model was done at Cal Tech by my kin, W. H. Bettes. There were many unique features of the aero design that are not being addressed in this forum.

Also kindly remember that most computer simulations rely on many assumptions and conclusions before the process of analysis. Such is the current buzz on the use of CFD in solving (tounge in cheek) flow problems.

I could say more, but will relax for a while and enjoy the high country snow.

My regards to all,
HB2

The 3 mph was for the Thrust II

...............and computer simulation today is something different to the stoneage 40 years ago.....may be you talk to Ron Ayers..............

[PorkPie]

Gentlemen,

Kindly note that the Goldenrod went at least 425mph on junk salt and not even in high gear! Also note that there were two noses built. I do not agree with the lift comments and about the 3 more mph being closer to the precipice of disaster. The aero testing on the scale model was done at Cal Tech by my kin, W. H. Bettes. There were many unique features of the aero design that are not being addressed in this forum.

Also kindly remember that most computer simulations rely on many assumptions and conclusions before the process of analysis. Such is the current buzz on the use of CFD in solving (tounge in cheek) flow problems.

I could say more, but will relax for a while and enjoy the high country snow.

My regards to all,
HB2

Very strange.......was it not Walter Korff who tooks care for the aerodynamic and testing programm???

[Harold Bettes]

Gentlemen,

I did not initmate that my kindred did any design work on the Goldenrod, just aero work in the tunnel (also some suggestions on how to apply the tunnel data). That work was done in the GALCIT 10ft tunnel that was in use at Caltech for 68yrs.

There is a photo of the two brothers in the CALTECH wind tunnel with the scale model of the Goldenrod that is at the site for HRM http://www.hotrod.com/featuredvehicles/113_0505_summers_brothers_goldenrod/engine.html

I have a lot more information than the old b&w taken there on Nov 18, 1964.

There is a great story about the air intake scoops and some politics and pouts associated, but that will keep til another day.

Regards,
HB2

[SPARKY]

   Great Stuff Guys---Good lord,  I feel like such a uninformed newbee!!!

[Super Kaz]

"Theoretical records are set by theoretical projects."

Round, low , heavy, with very little spring ?
Are you talking about My "Dunlap"?

Dunlap: The part of your round belly that DUNLAPPED over yer belt.

I heard of that Thing,but is it Real ?

[PorkPie]

When the Golden Rod was in the backyard from Don Green, the car was not so dirty.

Also not when it was on show display, during the time when he was on tour with Bill.

The windtunnel model shows not the later shape as used at Bonneville - a copy of this windtunnel model was for a long time in Richard Dixon's museum in Wendover - painted in white/blue/red - the color of a sponsor who was interest to use this car for another attempt - but at last it was not released on lack of the necessary money.

We used for the simulation the shape of the 425 mph run. The record version with his airbrakes - means air intake scoops which the Chrysler engineers liked to be used - would be different - and may be more worst.

When they checked the 425 mph version with the computerprogram it showed the effect of lifting. To find out how the lifting can be reduced, they modified the shape of the computer datas. When the nose  - means the front line of the nose - was 2 inches closer to the ground, the effect was nearly gone.

May be some people can remember the picture after the first high speed runs when the nose body work collapsed - by the way, Tom Burkland got in the 411 nose also a dent from the high speed pressure.