320:
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392:; 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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69:; 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.
296:-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
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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.
440:
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
80:
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
358:
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
423:
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
402:
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
269:, 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.
137:
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
435:
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
367:. 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,
52:
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,
128:
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
43:
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.
265:(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
226:
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
387:
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
436:
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
200:"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..."
339:. 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
231:. 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.
379:(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
210:
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
441:
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
411:"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
88:
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
253:
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,
603:
72:
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
292:. 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
65:
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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180:, demonstrating the functionality of the ground effect at that scale. In 2023, the Pronello Huayra chassis #002 was invited to the
81:
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.
173:
450:
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S. Buckley, "Vehicle Surface Interaction" Ph.D. Dissertation, University of California - Berkeley, Sept., 1972
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31:, particularly in racing cars. This has been the successor to the earlier dominant aerodynamic focus on
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133:"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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192:, where a complete aerodynamic analysis was carried out by the argentine engineer and professor
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375:, reached an agreement with other teams to withdraw the car after three races. However the
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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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790:"George Russell reveals chest pain from Mercedes porpoising at Emilia Romagna GP"
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578:"Pronello Huayra Ford: el primer auto de competición con efecto suelo del mundo"
553:"Pronello Huayra Ford: el primer auto de competición con efecto suelo del mundo"
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struggled to get out of the car after the race due to violent porpoising.
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628:"Huayra Pronello Ford: Argentinian sensation | Classic & Sports Car"
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604:"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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284:. 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
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335:'wing car', based on a concept from Lotus owner and designer
61:
This kind of ground effect is easily illustrated by taking a
528:"Viejas Automundo: Revista Automundo Nº 154 - 16 Abril 1968"
324:
246:
Rear of Chaparral 2J with large dual suction fan exhausts
739:"Mulsanne's Corner: Peter Elleray on the Bentley LMGTP"
764:"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
331:
In 1977 Rudd and Wright, now at Lotus, developed the
23:
is a series of effects which have been exploited in
359:depression under the car. It raced just once, with
832:Autocourse History of the Grand Prix car 1966–1985
403:between over the car downforce and ground effect.
398:The effect was used in its most effective form in
327:used a large fan to reduce underbody air pressure.
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347:. The most notable contender in 1978 was the
608:Automotive Testing Technology International
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371:, who had recently become president of the
300:, Buckley worked with Lotus developing the
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92:which is apparent in aircraft at very low
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377:Fédération Internationale de l'Automobile
157:category, making its first appearance in
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307:On a different tack, Brabham designer
276:on undercar aerodynamics sponsored by
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762:Mitchell, Scott (24 February 2022).
373:Formula One Constructors Association
855:Photoessayist.com: The Chaparral 2J
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443:2022 Formula One World Championship
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602:Brook-Jones, Callum (2023-07-26).
526:Automundo, Viejas (8 April 2013).
311:used air dams at the front of his
288:, Jerry Eisert's "Bat Car" of the
274:University of California, Berkeley
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238:Chaparral 2J at Goodwood historic
872:8W: Brabham-Alfa BT46B "fan car"
174:Fábrica Militar de Aviones (FMA)
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632:www.classicandsportscar.com
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188:, the car was taken to the
39:series and American racing
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455:2022 Azerbaijan Grand Prix
182:Goodwood Festival Of Speed
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702:8W - Why? - Brabham BT46B
551:Autocosmos (2023-07-17).
481:Ground effect in aircraft
280:, founder of Formula One
206:“The tests we did in the
161:for the 1969 season with
155:Sport Prototipo Argentino
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584:(in Spanish). 2023-07-16
176:usually employed by the
124:developed and built his
834:, Hazleton publishing,
471:Automotive aerodynamics
365:1978 Swedish Grand Prix
145:designer and engineer,
138:branches of the sport.
25:automotive aerodynamics
904:Motorsport terminology
877:Dennis David: Lotus 79
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341:de Havilland Mosquito
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290:1966 Indianapolis 500
263:British Racing Motors
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184:. During its stay in
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67:Bernoulli's principle
16:Aerodynamic principle
812:Henry, Alan (1985),
151:Pronello Huayra-Ford
116:Pronello Huayra-Ford
35:. The international
486:Ground-effect train
178:Argentine Air Force
882:2011-06-05 at the
865:2014-12-26 at the
830:Nye, Doug (1985),
715:, pp. 186–187
383:and gave teammate
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147:Heriberto Pronello
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743:Mulsanne's Corner
369:Bernie Ecclestone
267:March Engineering
167:Carlos Pascualini
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208:Catesby Tunnel
202:Rinland said.
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33:streamlining
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774:24 February
251:Formula One
229:Willem Toet
37:Formula One
893:Categories
816:, Osprey,
800:2022-04-27
748:2017-10-21
713:Henry 1985
637:2024-04-17
613:2024-04-17
588:2024-04-17
563:2024-04-17
557:Autocosmos
537:2024-04-17
497:References
407:Porpoising
361:Niki Lauda
353:Alfa Romeo
135:two-stroke
27:to create
582:AUTOMUNDO
453:. At the
255:Tony Rudd
224:downforce
143:argentine
126:Chaparral
120:American
94:altitudes
74:viscosity
63:tarpaulin
29:downforce
880:Archived
863:Archived
768:The Race
725:Nye 1985
690:Nye 1985
678:Nye 1985
514:Nye 1985
465:See also
438:porpoise
432:teams).
430:Merzario
417:Lotus 78
345:Lotus 79
333:Lotus 78
302:Lotus 78
220:diffuser
153:for the
122:Jim Hall
41:IndyCars
426:Kauhsen
400:IndyCar
349:Brabham
294:Venturi
286:IndyCar
186:England
159:Córdoba
100:History
55:'wings'
838:
820:
48:Theory
356:BT46B
325:BT46B
282:Lotus
211:time”
836:ISBN
818:ISBN
776:2022
428:and
419:and
390:1982
257:and
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