Shape shifting spoilers ??

[aerohead]

Originally Posted by Cd

Here is concept vehicle using the devices that I was talking about in my first post. :
Shape-Shifting Hybrids - The Vauxhall Flextreme Hits 125 MPH While Getting 175 MPG (VIDEO)

QUOTE " The most surprising thing about the Vauxhall Flextreme is the fact that it shape-shifts at certain speeds. When the car goes above 30 MPH a vertical panel extends along the body and behind the wheels to make the car have more drag co-efficient."

( I see a typo there ... that should say LESS drag )

This is a low quality video of the car. Note what the announcer says about how the back end extends at speed :

Here is a much better view of the same car.
Note the use of clear inserts in the wheels between the spokes and the plugged grille up front.
Also, note the use of small cameras where the mirrors would be. They didn't talk about the shape shifting abilities of the car, but it's a good view of the car never the less.

Why is it that Opel ( a division of GM ) makes such beautiful streamlined designs, while we here in the U.S. are handed asymmetrical bricks on wheels ?

The OPEL Insignia was sold fairly recently in the USA by GM's Buick Division, as was the OPEL GT in 1969, and OPEL Kadett, as a Chevy Chevette in the 1970s into 1980s, along with others my memory can't serve.

[aerohead]

Complicate and subtract lightness.

[freebeard]

The video that might explain is is set to Private.

2008 Opel Vauxhall Flextreme Concept promotional video is absoloutely no help. The only thing it show that's retractable are the cup holders ....and a Segway garage.

What about the BMW Gina?

https://en.wikipedia.org › wiki › BMW_GINA
BMW GINA - Wikipedia
The GINA Light Visionary Model is a fabric-skinned shape-shifting sports car concept built by BMW. GINA stands for "Geometry and functions In 'N' Adaptions". [1] [2] [3] It was designed by a team led by BMW's head of design, Chris Bangle, who says GINA allowed his team to "challenge existing principles and conventional processes." [1]

[aerohead]

* 1912 Deperdussin Monocoque aircraft introduces 'MOON' wheel covers, and head-fairing.
* November 11, 1916, Cornelius T. Meyers introduces active extensible boat-tail, US PATENT 1,352,679.
* circa 1935, Baron Reinhard von Koenig-Fachsenfeld reintroduces an active, extensible boat-tail and splitter.
* 1935 Reid Railton introduces the variable radiator shutter on Sir Malcolm Campbell's Bluebird LSR race car.
* 1947 Reid Railton introduces 100% grille-block with ice-tank-cooled engine on his Railton MOBIL Special LSR racer.
* 1955 Ford convertible offers Cd - 0.55 -to- Cd 0.85.
* 1957 tilt-wing aircraft R&D is underway.
* 1961, first rear spoiler introduced by Richie Ginther, fine-tuned by Mauro Forghieri, Ferrari 2643 prototype, 24-Hours of Le Mans.
* 1966 VW Beetle convertible offers Cd 0.50-to-Cd - 0.68.
* 1966 VW Karmann-Ghia convertible offers Cd 0.38- to - Cd 0.48.
* 1967 Chevy Chaparal 2F introduces active, variable angle-of-attack wing.
* 1970 Volvo VCC concept introduces an active airdam.
* 1970 Porsche 914:
- Cd 0.017 pop-up headlights
- Cd 0.018 side windows down
- Cd 0.026 roof removal
* 1972, first 'production' rear spoiler, homologated Porsche 911 RS 2.7.
* 1976 Ford of Cologne, Germany introduces 'lamellar' passive-active grille-shutter.
* c 1979, Daimler- Benz C-111-IV introduces variation of Fachsenfelds' splitter.
* 1983 Ford Probe-III incorporates an active deployable front valance.
* 1983 GM Aero 2000 ( Epcot car ) concept introduces active rear diffuser.
* 1983 Ford Prove-IV concept incorporates active front airdam, active chassis inclination aero-optimizing suspension, and inner fender/ elastic urethane rubber front wheel skirts.
* 1987 GM Pontiac Pursuit concept incorporates articulated front wheel skirts, and computer-controlled DELCO air suspension.
1987 Renault Vesta II concept uses active air suspension for drag reduction.
* 2002 VW 1-Liter car introduces active, variable-opening, submerged NACA cooling system inlet.
* 2013 Ford F-150 'ATLAS' concept introduces active, battery-powered wheel shutters.
* Ferrari introduces drag-reducing 'aero-bridge', by PININFARINA, on F12
* Dodge RAM 1500 HFE offers active air suspension for drag reduction.
* 2016 Mercedes-Benz IAA re-introduces active, extensible rear elongation, and active, morphing wheel shutters.
* 2022 Mercedes-Benz Vision EQXX active, extensible rear diffuser.

[Cd]

Ahh yes !
I forgot about those.

BTW, I think the reason some of the links no longer work here, is that I posted this 13 years ago.

[aerohead]

I snuck in some additional aero tools above at #24 (permalink).

[j-c-c]

I believe a few years back I tossed this idea out here and don't remember getting much feedback. My project touches slightly on the Op's goals I think. My application is a full body sedan track car, that I mainly want as much DF with as little drag as possible on a closed road course at speeds 60-120mph. The rear window/deck area will always have turbulent air flow. Installing a real rear wing is mainly useful when getting it into some clean air, but that height unfortunately by simple drag reduces front measured DF. Since dF is a friend at the rear on braking and early acceleration, it would nice if the wing was effective under those conditions and not so much at other times.

My thinking was if I could find the optimum mounting height for the wing, could I coax the rear deck airflow under the wing on braking and let the air flow revert back above the wing and thereby reducing drag when the wing is not helpful. I would attempt to do this by using oversize rear brake cooling fans to remove the boundary air from the rear turn down area of the top of the rear window, and try to redirect/reshape the air approaching the rear wing.

It would be easy to actuate as it would trigger a solenoid off the rear brake line pressure and have an adjustable delay after pressure on the brakes is released, to allow for extra whatever DF is available, as the car accelerates out of a turn/braking zone.

The actuation of the brake fans seemingly coincides rather well with the cooling needs/timing for the rear brakes.

The question here centers on, will this solution redirect the air enough and can I remove enough air to redirect the airflow enough with cooling fans to take the wing in and out of play to achieve my goals.

[freebeard]

a full body sedan track car

What sanctioning body? What type of track?

...using oversize rear brake cooling fans to remove the boundary air from the rear turn down area of the top of the rear window,

You would pull air into the wheelwells?

The only thing I can think of to compare is the MacLaren T50. Maybe it would indicate the amount of fan power necessary.

Prolly involves reshaping the wheelwell exit as well.

[j-c-c]

It's a track/fun car, no rules other than safety. Air would be moved to the wheel wells. Car currently has a robust diffuser which might capture benefit/assist the extra relocated air's removal. Keep in mind, moving the airstream say 3in vertically 48" behind the roof line achieves my goals I believe. I already have two 1200CFM drivetrain/engine oil coolant exhaust fans sucking air directly from over the rear live axle, exhausting out thru the back of the trunk lid

Current typical large in line brake fans on the market move approx 400Cfm ea x2, but remember this extra airflow directed to the wells is only under braking, and only briefly under acceleration.
My thinking is a Plexiglas tube connected plenum with many small holes patterned across the upper surface of say an 8in extension of the rear roofline with its angle set to where I want the airflow to be directed, when the rear wing needs maximum clean airflow. Fine tuning wing height for this objective will be critical and maybe a bit of a compromise for the speed ranges intended.

[aerohead]

Out of courtesy I wanted to touch base.
I've read, and re-read your post.
Ferrari did a project like yours in the past, and it ended with 1,000-hours in the wind tunnel, at $1,000 / hour, plus track time in Modena, to evaluate all the the transient dynamics and loadings, with respect to drag and downforce, for all locations along the race course.
If you're a millionaire, then you'd be able to absorb the economic and human capital costs such a sophisticated project like yours would involve to reach a solution.
My dad knew a race driver who operated a speed shop in Southern California. When a prospective client would ask him, 'How fast can you make my car go?', his response was always,' How much money do you have?'
Presently, a full-scale, rolling-road wind tunnel is going to set you back $4,000 /hour.
I don't know what you could possibly do without one.
And to hire someone with at least a graduate degree in CFD, and years of experience, I don't know how you could afford to attempt it 'virtually.'
I don't mean to be a buzz-kill, but reality IS going to intrude upon your dreams, and they're EXPENSIVE ones.