The "Kamm-back" (K-form)

[ecomodded]

quote aerohead :, Here,you can see how Carl Breer attempted to blend the 1934 DeSoto Airflow test mules fenders into the body a little better.
For all the mods,they went from Cd 0.51,to 0.244,about what Elon Musk gets with today's Tesla S.
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The car looks huge , that is a great accomplishment , I notice the fenders flairs are blended up into the body.
The Nose is one of those rarely discussed areas on the cars areo, it has a similar nose to the beetle, well somewhat ...

The Boxfish and the Vesta 2 are nearly identical as expected with nearly identical cd's
It looks like a very useful shape , space wise or useful cu. ft.
It's a surprising design for such low cd , its so so squat and works so well.

I am doing a kammback model on a 1/32 scale cast model of a New Beetle.
I did the bulk of it yesterday , let it dry and sanded . one more coat and some dry time and a little detailing and I will post it.

I am using a drywall seam sealer , a type of poly filler , to form the kammback on the Model.

[ecomodded]

Originally Posted by freebeard

Another one from the album

Rear fender remodeled based on The Template, The top should copy the B-pillar shape and just shrink it as it goes back.

I can see the practicality of your designs direction.
With the Beetles narrow top and wide body, it pretty much demands to be split into two separate applications.

I will have to mod my rear fender flairs to help blend it , or it will be a wide body no slope design.


edit:
I see what you have done ,you made the rear fender A boattail , I like that idea , a spoiler but better a boattail stick on.

[freebeard]

I threw together 4 (previously unseen?) views.



The idea with the bottom section (which looks a little big now) was that the area at the truncation is equal to the area through the axle line, but the air has been [smoothed/set up] by the plan taper when it hits the box cavity.

[ecomodded]

I am making a Kammback on a 1/32 cast model of the New Beetle and right now it looks about identical to the bottom right diagram minus the wheel arch treatments.
I am using a Drywall seam sealer, its like poly filler, for the models kammback.
One more sanding and detailing and it will be done, it has to set for 24hrs before I can sand again.

[aerohead]

I've added three new images on page-1,at the bottom of the first permalink.

[freebeard]

It needs an ecomodder logo on the door.

Any ideas on the tailfins. Is the front canard to 'stallproof' it? It looks like the front fin has greater fineness ration and is staggered inward. And possibly different dihedral.

[aerohead]

Originally Posted by freebeard

It needs an ecomodder logo on the door.

Any ideas on the tailfins. Is the front canard to 'stallproof' it? It looks like the front fin has greater fineness ration and is staggered inward. And possibly different dihedral.

So far,there's no specific data on the fins.But Kamm really liked these things.

[freebeard]

This looks similar to the Bertone BAT cars, except the two components aren't joined at the top. I still don't get how the canard sets up the airfoil behind it.



At Bonneville they didn't seem to allow non-longitudinal fences and diverters, although I did see one exception.

[aerohead]

Originally Posted by freebeard

This looks similar to the Bertone BAT cars, except the two components aren't joined at the top. I still don't get how the canard sets up the airfoil behind it.



At Bonneville they didn't seem to allow non-longitudinal fences and diverters, although I did see one exception.

If I had to guess (and I am),the split fin develops the desired center of pressure/center of gravity bias in a steady crosswind,but in a strong gust,it allows the air pressure to bleed through the gap so as not to generate a roll moment,which would be equally freaky.
Gust stability was a big issue for Kamm and Fachsenfeld.They parked Junkers Ju52s along a stretch of roadway,with their propeller slipstreams blasting across the pathway.If a passing vehicle didn't go out of control,it passed the 'smell test' for directional stability.Same for racing cars which they also designed.
Hitler's Autobahn and Mussolini's Autostrada allowed really high speed driving for the first time and they didn't want motorists getting themselves killed.I think Ferdinand Porsche drove at 90 mph in his 60K10,between Stuttgart and Berlin.

[aerohead]

One photo was MIA so I've restored it,along with a shot of Kamm's personal car with Fachsenfeld's patented split-wings,and also a tuft study of the same car which appeared in HOT ROD Magazine in the 60s.
They are the 6th,7th,and 8th down from the top of the thread.