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403:; flat undersides became mandatory for 1983. Part of the danger of relying on ground effects to corner at high speeds is the possibility of the sudden removal of this force; if the underside of the car contacts the ground, the flow is constricted too much, resulting in almost total loss of any ground effects. If this occurs in a corner where the driver is relying on this force to stay on the track, its sudden removal can cause the car to abruptly lose most of its traction and skid off the track.
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80:; as the tarp gets closer to the ground, the cross sectional area available for the air passing between it and the ground shrinks. This causes the air to accelerate and as a result pressure under the tarp drops while the pressure on top is unaffected, and together this results in a net downward force. The same principles apply to cars.
307:-like channel beneath the cars sealed by flexible side skirts that separated the channel from above-car aerodynamics. He investigated how flow separation on the undersurface channel could be influenced by boundary layer suction and divergence parameters of the underbody surface. Later, as a mechanical engineering professor at
68:
were routinely used in the design of race cars to increase downforce (which is not a type of ground effect). Designers shifted their efforts at understanding air flow around the perimeter, body skirts, and undersides of the vehicle to increase downforce with less drag than compared to using a wing.
451:
diving into and out of the sea as it swims at speed, gives the phenomenon its name. These characteristics, combined with a rock-hard suspension, resulted in the cars giving an extremely unpleasant ride. Ground effects were largely banned from
Formula One in the early 1980s until 2022, but Group C
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in 1974 to exclude air from flowing under the vehicle. Upon discovering that these tended to wear away with the pitching movement of the car, he placed them further back and discovered that a small area of negative pressure was formed under the car, generating a useful amount of downforce - around
91:
between the two surfaces works to slow down the air between them which lessens the
Bernoulli effect. When a car moves over the ground, the boundary layer on the ground becomes helpful. In the reference frame of the car, the ground is moving backwards at some speed. As the ground moves, it pulls on
369:
Fancar, designed by Gordon Murray. Its fan, spinning on a horizontal, longitudinal axis at the back of the car, took its power from the main gearbox. The car avoided the sporting ban by claims that the fan's main purpose was for engine cooling, as less than 50% of the airflow was used to create a
434:
cars demonstrated that ground effect was the future in
Formula One, so, at this point, under-car aerodynamics were still very poorly understood. To compound this problem the teams that were very keen to pursue ground effects tended to be the more poorly funded British "garagista" teams, who had
413:
designs. IndyCars did not use ground effect as substantially as
Formula One. For example, they lacked the use of skirts to seal off the underbody of the car. IndyCars also rode higher than ground effect F1 cars and relied on wings for significant downforce as well, creating an effective balance
280:, on a suggestion from Wright, used a similar concept on the 1970 March Formula One car. In both cars the sidepods were too far away from the ground for significant ground effect to be generated, and the idea of sealing the space under the wing section to the ground had not yet been developed.
148:
engine; it also had "skirts", which left only a minimal gap between car and ground, to seal the cavity from the atmosphere. Although it did not win a race, some competition had lobbied for its ban, which came into place at the end of that year. Movable aerodynamic devices were banned from most
446:
This led to a generation of cars that were designed as much by hunch as by any great knowledge of the finer details, making them extremely pitch-sensitive. As the centre of pressure on the sidepod aerofoils moved about depending on the car's speed, attitude, and ground clearance, these forces
378:. The car's advantage was proven after the track became oily. While other cars had to slow, Lauda was able to accelerate over the oil due to the tremendous downforce which rose with engine speed. The car was also observed to squat when the engine was revved at a standstill. Brabham's owner,
63:
In racing cars, a designer's aim is for increased downforce and grip to achieve higher cornering speeds. A substantial amount of downforce is available by understanding the ground to be part of the aerodynamic system in question, hence the name "ground effect". Starting in the mid-1960s,
139:
cars around the principles of ground effects, pioneering them. His 1961 car attempted to use the shaped underside method but there were too many other aerodynamic problems with the car for it to work properly. His 1966 cars used a dramatic high wing for their downforce. His
54:
employ ground effects in their engineering and designs. Similarly, they are also employed in other racing series to some extent; however, across Europe, many series employ regulations (or complete bans) to limit its effectiveness on safety grounds.
276:(BRM) experimented on track and in the wind tunnel with long aerodynamic section side panniers to clean up the turbulent airflow between the front and rear wheels. Both left the team shortly after and the idea was not taken further. Robin Herd at
237:
you can get from a diffuser. The car was at the tunnel with pressure tapings added to it, in order to look at the pressure distribution around the car which looks to completely confirm that it works exactly as the designer expected.”, explained
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a posthumous second place, demonstrating just how much of an advantage the cars had. In the following years other teams copied and improved on the Lotus until cornering speeds became dangerously high, resulting in several severe accidents in
447:
interacted with the car's suspension systems, and the cars began to resonate, particularly at slow speeds, rocking back and forth - sometimes quite violently. Some drivers were known to complain of sea-sickness. This rocking motion, like a
211:"We always thought it had ground effect... When Heriberto tested it at the National University of Córdoba, he verified its air resistance with a 1/5 scale model that was perfect, without door and hood openings, without the intake turrets..."
350:. Its sidepods, bulky constructions between front and rear wheels, were shaped as inverted aerofoils and sealed with flexible "skirts" to the ground. The design of the radiators, embedded into the sidepods, was partly based on that of the
242:. These tests were carried out with and without the "long tail" which was used for high-speed circuits, with the vehicle propelled by its own means, at working temperature, returning consistent and repeatable results.
390:(FIA), governing body of Formula One and many other motorsport series, decided to ban 'fan cars' with almost immediate effect. The Lotus 79, on the other hand, went on to win six races and the world championship for
221:
demonstrated its great aerodynamic efficiency: we obtained a Cx 0.25 with the short tail and a Cx 0.23 with the long tail, which it used on the fastest circuits. Almost, almost what
Heriberto had measured at the
452:
sportscars and other racing cars continued to suffer from porpoising until better knowledge of ground effects allowed designers to minimise the problem. At the first pre-season test in
Barcelona ahead of the
422:"Porpoising" is a term commonly used to describe a particular fault encountered in ground-effect racing cars. Racing cars had only been using their bodywork to generate downforce for just over a decade when
99:
While such downforce-producing aerodynamic techniques are often referred to with the catch-all term "ground effect", they are not strictly speaking a result of the same aerodynamic phenomenon as the
264:
was the next setting for ground effect in racing cars. Several
Formula One designs came close to the ground-effect solution which would eventually be implemented by Lotus. In 1968 and 1969,
614:
83:
The
Bernoulli principle is not the only aspect of mechanics in generating ground-effect downforce. A large part of ground-effect performance comes from taking advantage of
303:. By proper shaping of the car's underside, the air speed there could be increased, lowering the pressure and pulling the car down onto the track. His test vehicles had a
387:
76:
out on a windy day and holding it close to the ground: it can be observed that when close enough to the ground the tarp will be drawn towards the ground. This is due to
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said extreme porpoising could lead to safety issues and later stated he was suffering from chest pain due to extreme porpoising during the
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191:, demonstrating the functionality of the ground effect at that scale. In 2023, the Pronello Huayra chassis #002 was invited to the
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the air above it and causes it to move faster. This enhances the
Bernoulli effect and increases downforce. It is an example of
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that gave it quite an edge in its day. The diffuser has an expansion ratio that puts it staggeringly close to the maximum
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little money to spare for wind tunnel testing, and tended simply to mimic the front-running
Lotuses (including the
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After a forty-year ban, ground effect returned to Formula 1 in 2022 under the latest set of regulation changes.
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S. Buckley, "Vehicle Surface Interaction" Ph.D. Dissertation, University of California - Berkeley, Sept., 1972
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42:, particularly in racing cars. This has been the successor to the earlier dominant aerodynamic focus on
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144:"sucker car" of 1970 was revolutionary. It had two fans at the rear of the car driven by a dedicated
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aircraft. The team won five races that year, and two in 1978 while they developed the much improved
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B. Shawn Buckley, Edmund V. Laitone, "Air Flow Beneath an Automobile", SAE paper 741028, 1974-02-01
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70 kg (150 lb). McLaren produced similar underbody details for their McLaren M23 design.
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203:, where a complete aerodynamic analysis was carried out by the argentine engineer and professor
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B. Shawn Buckley, "Road Test Aerodynamic Instrumentation", SAE paper 741030, 1974-02-01
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During 1968, a 1/5 scale model was made, which was tested in the wind tunnel of the
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801:"George Russell reveals chest pain from Mercedes porpoising at Emilia Romagna GP"
589:"Pronello Huayra Ford: el primer auto de competición con efecto suelo del mundo"
564:"Pronello Huayra Ford: el primer auto de competición con efecto suelo del mundo"
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87:. In the tarp example above, neither the tarp nor the ground is moving. The
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struggled to get out of the car after the race due to violent porpoising.
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639:"Huayra Pronello Ford: Argentinian sensation | Classic & Sports Car"
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615:"Huayra Pronello-Ford tested in Catesby Tunnel ahead of Goodwood FOS"
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At about the same time, Shawn Buckley began his work in 1969 at the
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295:. Buckley had previously designed the first high wing used in an
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Pronello Huayra-Ford, in its long tail, high speed configuration
346:'wing car', based on a concept from Lotus owner and designer
72:
This kind of ground effect is easily illustrated by taking a
539:"Viejas Automundo: Revista Automundo Nº 154 - 16 Abril 1968"
257:
Rear of Chaparral 2J with large dual suction fan exhausts
750:"Mulsanne's Corner: Peter Elleray on the Bentley LMGTP"
775:"F1 2022 car porpoising 'safety concern' at its worst"
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It has a slippery upper shape and a flat floor with a
342:
In 1977 Rudd and Wright, now at Lotus, developed the
34:
is a series of effects which have been exploited in
370:depression under the car. It raced just once, with
843:Autocourse History of the Grand Prix car 1966–1985
414:between over the car downforce and ground effect.
409:The effect was used in its most effective form in
338:used a large fan to reduce underbody air pressure.
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518:
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358:. The most notable contender in 1978 was the
8:
619:Automotive Testing Technology International
382:, who had recently become president of the
311:, Buckley worked with Lotus developing the
103:which is apparent in aircraft at very low
388:Fédération Internationale de l'Automobile
168:category, making its first appearance in
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318:On a different tack, Brabham designer
287:on undercar aerodynamics sponsored by
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773:Mitchell, Scott (24 February 2022).
384:Formula One Constructors Association
866:Photoessayist.com: The Chaparral 2J
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700:
688:
524:
454:2022 Formula One World Championship
613:Brook-Jones, Callum (2023-07-26).
537:Automundo, Viejas (8 April 2013).
322:used air dams at the front of his
299:, Jerry Eisert's "Bat Car" of the
285:University of California, Berkeley
25:
249:Chaparral 2J at Goodwood historic
883:8W: Brabham-Alfa BT46B "fan car"
185:Fábrica Militar de Aviones (FMA)
462:2022 Emilia Romagna Grand Prix
1:
871:VintageRPM: Chaparral history
825:Brabham, the Grand Prix Cars
643:www.classicandsportscar.com
199:, the car was taken to the
50:series and American racing
936:
466:2022 Azerbaijan Grand Prix
193:Goodwood Festival Of Speed
713:8W - Why? - Brabham BT46B
562:Autocosmos (2023-07-17).
492:Ground effect in aircraft
291:, founder of Formula One
217:“The tests we did in the
172:for the 1969 season with
166:Sport Prototipo Argentino
595:(in Spanish). 2023-07-16
187:usually employed by the
135:developed and built his
845:, Hazleton publishing,
482:Automotive aerodynamics
376:1978 Swedish Grand Prix
156:designer and engineer,
149:branches of the sport.
36:automotive aerodynamics
915:Motorsport terminology
888:Dennis David: Lotus 79
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352:de Havilland Mosquito
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301:1966 Indianapolis 500
274:British Racing Motors
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195:. During its stay in
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78:Bernoulli's principle
27:Aerodynamic principle
823:Henry, Alan (1985),
162:Pronello Huayra-Ford
127:Pronello Huayra-Ford
46:. The international
497:Ground-effect train
189:Argentine Air Force
893:2011-06-05 at the
876:2014-12-26 at the
841:Nye, Doug (1985),
726:, pp. 186–187
394:and gave teammate
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158:Heriberto Pronello
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754:Mulsanne's Corner
380:Bernie Ecclestone
278:March Engineering
178:Carlos Pascualini
16:(Redirected from
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920:Vehicle dynamics
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270:Peter Wright
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142:Chaparral 2J
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94:Couette flow
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44:streamlining
31:
29:
785:24 February
262:Formula One
240:Willem Toet
48:Formula One
904:Categories
827:, Osprey,
811:2022-04-27
759:2017-10-21
724:Henry 1985
648:2024-04-17
624:2024-04-17
599:2024-04-17
574:2024-04-17
568:Autocosmos
548:2024-04-17
508:References
418:Porpoising
372:Niki Lauda
364:Alfa Romeo
146:two-stroke
38:to create
18:Porpoising
593:AUTOMUNDO
464:. At the
266:Tony Rudd
235:downforce
154:argentine
137:Chaparral
131:American
105:altitudes
85:viscosity
74:tarpaulin
40:downforce
891:Archived
874:Archived
779:The Race
736:Nye 1985
701:Nye 1985
689:Nye 1985
525:Nye 1985
476:See also
449:porpoise
443:teams).
441:Merzario
428:Lotus 78
356:Lotus 79
344:Lotus 78
313:Lotus 78
231:diffuser
164:for the
133:Jim Hall
52:IndyCars
437:Kauhsen
411:IndyCar
360:Brabham
305:Venturi
297:IndyCar
197:England
170:Córdoba
111:History
66:'wings'
849:
831:
59:Theory
367:BT46B
336:BT46B
293:Lotus
222:time”
847:ISBN
829:ISBN
787:2022
439:and
430:and
401:1982
268:and
176:and
426:'s
309:MIT
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