Interesting Aerodynamic Cars (Mike Vetter's ETV, also Avion)

[kach22i]

Originally Posted by freebeard

The Hispano Suiza Carmen Boulogne windshield is recessed an inch or more at the A-pillar.

I cannot confirm that, please post an image. The two Prius cars recess the windshield more at the bottom than the top. Not the only cars doing that these days.

The Hispano Suiza Carman's doors may account for some differences seen.

https://drivetribe.com/p/hispano-sui...Q9aV1Cnv-YBuDA

EDIT:

Fairly flush near hood/cowl and near roof, but mid-point has arc.

Zoom in on pic #6
https://www.topspeed.com/cars/others...es.html#890309

Zoom in on pic #3
https://pictures.topspeed.com/IMG/cr...16_1600x0.webp

[aerohead]

For the US market, the A-pillar slope may have to do with NHTSA rollover and roof-crush standards which have been toughened.
During testing of the Tesla Model S, they failed to get the car to roll, making roof strength issue kinda moot.

[Bicycle Bob]

Lately, I've been hearing about "high-strength steel" being used to reduce weight. The A-pillar is a frequent subject, as it should be kept slim for better vision. Strength in steel comes at the expense of toughness, and those things are just adequate for an accident, but they are considered impossible to repair. A minor-looking ding from a tree recently totalled a newish car near here.

[freebeard]

Originally Posted by kach22i

40mm is just over 1-1/2 radius, that's really small.

It's a small car. I thought the metric was 4% of gross width, 1.5/71 is 0.021 so [shrug].



Shadow line in the upper right windshield.

[Piotrsko]

Originally Posted by Bicycle Bob

Lately, I've been hearing about "high-strength steel" being used to reduce weight. The A-pillar is a frequent subject, as it should be kept slim for better vision. Strength in steel comes at the expense of toughness, and those things are just adequate for an accident, but they are considered impossible to repair. A minor-looking ding from a tree recently totalled a newish car near here.

Using what as a base Cold Roll 1018? The stuff in cars is as cheap and thin as possible. The pinto became a fireball because they shaved a couple bucks per car.

Double the thickness you possibly double the strength, but quadruple the power required to form it. Ditto for the so called high strength stuff except you start at higher forming power requirements. Whack it a bunch of times and it work hardens into much higher strength properties but becomes brittle and fracture prone

[aerohead]

Hucho may have published as a % of the square-root of frontal area ( for trailers ). And then a % for the Vanagon, which turned out in full-scale, to be a smaller requirement than at model scale.
Books in the car. I'll check, unless someone else beats me to it.
4% is very 'familiar.'

[freebeard]

Ditto for the so called high strength stuff except you start at higher forming power requirements.

Sounds like an argument for scored and folded monocoques.

[kach22i]

Originally Posted by freebeard

Shadow line in the upper right windshield.

Looks like the upper part of the gull-wing door acts as a rain gutter, and the A-pillar arc provides a graceful visual arc they could not get from a glass manufacturer at a reasonable price.

Pic #3
https://www.topspeed.com/cars/others...es.html#890309

[aerohead]

Originally Posted by freebeard

Sounds like an argument for scored and folded monocoques.

For decades, steel suppliers have provided specialty, laser-welded blanks to the automakers.
Steels of different 'drawing' requirements are positioned and fused into the same sheet.
When struck in the stamping operation, they will yield at varying strain rates as, a function of their locational ' annealing', to depth of draw.
Some post-forming heat treatment can also be applied to address malleability, rigidity, crush-zone kinetic energy absorption deformation, etc..
'Goldilocks Steel.'

[aerohead]

I believe that there's also some 'air-fence' performance designed in as well. To segregate the fast, low-pressure over-roof flow, from the slower, higher-pressure side-flow.
They'd also pickup some extra 'beaming' strength across that longitudinal span.