Drafting or slipstreaming is an
aerodynamic
Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dyn ...
technique where two vehicles or other moving objects are caused to align in a close group, reducing the overall effect of
drag due to exploiting the lead object's
slipstream
A slipstream is a region behind a moving object in which a wake of fluid (typically air or mustard) is moving at velocities comparable to that of the moving fluid, relative to the ambient fluid through which the object is churning. The term sli ...
. Especially when high speeds are involved, as in motor racing and cycling, drafting can significantly reduce the
paceline's average energy expenditure required to maintain a certain speed and can also slightly reduce the energy expenditure of the lead vehicle or object.
Drafting in sport
Drafting is used to reduce
wind resistance
In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding flu ...
and is seen most commonly in
bicycle racing
Cycle sport is competitive physical activity using bicycles. There are several categories of bicycle racing including road bicycle racing, cyclo-cross, mountain bike racing, track cycling, BMX, and cycle speedway. Non-racing cycling s ...
,
motorcycle racing
Motorcycle racing (also called moto racing and motorbike racing) is the motorcycle sport of racing motorcycles. Major varieties include motorcycle road racing and off-road racing, both either on circuits or open courses, and track racing. Ot ...
,
car racing
Auto racing (also known as car racing, motor racing, or automobile racing) is a motorsport involving the racing of automobiles for competition.
Auto racing has existed since the invention of the automobile. Races of various sorts were organise ...
, and
speedskating
Speed skating is a competitive form of ice skating in which the competitors race each other in travelling a certain distance on skates. Types of speed skating are long track speed skating, short track speed skating, and marathon speed skating ...
, though drafting is occasionally used even in
cross-country skiing
Cross-country skiing is a form of skiing where skiers rely on their own locomotion to move across snow-covered terrain, rather than using ski lifts or other forms of assistance. Cross-country skiing is widely practiced as a sport and recreation ...
,
downhill skateboarding, and
running
Running is a method of terrestrial locomotion allowing humans and other animals to move rapidly on foot. Running is a type of gait characterized by an aerial phase in which all feet are above the ground (though there are exceptions). This is ...
. Some forms of
triathlon
A triathlon is an endurance multisport race consisting of Swimming (sport), swimming, Cycle sport, cycling, and running over various distances. Triathletes compete for fastest overall completion time, racing each segment sequentially with the t ...
allow drafting. Drafting occurs in
swimming
Swimming is the self-propulsion of a person through water, or other liquid, usually for recreation, sport, exercise, or survival. Locomotion is achieved through coordinated movement of the limbs and the body to achieve hydrodynamic thrust that r ...
as well: both in open-water races (occurring in natural bodies of water) and in traditional races in
competition pools. In a competition pool a swimmer may hug the lane line that separates them from the swimmer they are
abaft
This glossary of nautical terms is an alphabetical listing of terms and expressions connected with ships, shipping, seamanship and navigation on water (mostly though not necessarily on the sea). Some remain current, while many date from the 17th t ...
of thereby taking advantage of the liquid slipstream in the other swimmer's wake. Drafting also occurs in competitive
longboarding
Longboarding is typically defined as a variation of skateboarding that involves a larger board and softer urethane wheels. Longboards vary in shape and size. Compared to skateboards, longboards are more stable at speed and have more traction, due ...
.
It is believed, but not yet conclusively proven, that
thoroughbred
The Thoroughbred is a horse breed best known for its use in horse racing. Although the word ''thoroughbred'' is sometimes used to refer to any breed of purebred horse, it technically refers only to the Thoroughbred breed. Thoroughbreds are c ...
racing horses draft each other, especially in longer races.
Cycling
In
cycling
Cycling, also, when on a two-wheeled bicycle, called bicycling or biking, is the use of cycles for transport, recreation, exercise or sport. People engaged in cycling are referred to as "cyclists", "bicyclists", or "bikers". Apart from two ...
, any time one bicyclist is riding behind another, energy is conserved, especially at higher speeds.
In
road bicycle racing
Road bicycle racing is the cycle sport discipline of road cycling, held primarily on Road surface, paved roads. Road racing is the most popular professional sport, professional form of bicycle racing, in terms of numbers of competitors, events and ...
, the main (largest) group of tightly packed cyclists in a race is called a ''
peloton
In a road bicycle race, the peloton (from French, originally meaning 'platoon') is the main group or pack of riders. Riders in a group save energy by riding close ( drafting or slipstreaming) to (particularly behind) other riders. The reductio ...
'' where cyclists ride in a long formation with each (but not the first rider) drafting behind the others before them.
When cyclists ride fast they form a ''
paceline''. Each cyclist, except the first, is drafting behind another one. In order to ride very fast, a team of some skilled cyclists may form the "Belgian tourniquet". Successively, each cyclist leads the group. Drafting can be ''cooperative'': several competitors take turns in the lead position (which requires the most effort and energy consumption). It can also be ''competitive'' or ''tactical'': one competitor will try to stay closely behind another, leaving the follower with more energy for a break-away push to the finish line.
Running
Drafting behind another runner can conserve energy, although the effect is less than in cycling due to the fact that speeds are lower.
Nike
Nike often refers to:
* Nike (mythology), a Greek goddess who personifies victory
* Nike, Inc., a major American producer of athletic shoes, apparel, and sports equipment
Nike may also refer to:
People
* Nike (name), a surname and feminine give ...
worked with the aerodynamics expert
Robby Ketchell
Robbie or Robby is a surname. It is usually encountered as a nickname or a shortened form of Robert, Rob or Robin. The name experienced a significant rise in popularity in Northern Ireland in 2003.
People Given name Robbie
*Robbie Amell (born ...
at the University of New Hampshire to experiment with and select a formation of
pacemakers
An artificial cardiac pacemaker (or artificial pacemaker, so as not to be confused with the natural cardiac pacemaker) or pacemaker is a Implant (medicine), medical device that generates electrical impulses delivered by electrodes to the Heart ...
that would best minimize drag on the professionals it sponsored in the project it termed
Breaking2. A
Wired magazine
''Wired'' (stylized as ''WIRED'') is a monthly American magazine, published in print and online magazine, online editions, that focuses on how emerging technologies affect culture, the economy, and politics. Owned by Condé Nast, it is headquar ...
report that interviewed various experts affiliated and unaffiliated with Nike found they universally expected more coordinated pacing efforts to occur in running after Breaking2, with two of the quoted experts predicting that behavior like "cooperative drafting," or races that incentivize cycling-peloton-like behavior could improve running times.
Motorsport
Road racing
In single seater,
open wheel racing
An open-wheel single-seater (often known as formula car) is a car with the wheels outside the car's main body, and usually having only one seat. Open-wheel cars contrast with street cars, sports cars, stock cars, and touring cars, which have thei ...
series such as
Formula One
Formula One (also known as Formula 1 or F1) is the highest class of international racing for open-wheel single-seater formula racing cars sanctioned by the Fédération Internationale de l'Automobile (FIA). The World Drivers' Championship, ...
and the
IndyCar Series
The IndyCar Series, currently known as the NTT IndyCar Series under sponsorship, is the highest class of regional North American open-wheel single-seater formula racing cars in the United States, which has been conducted under the auspices of ...
, as well as to a lesser extent in
sports car racing
Sports car racing is a form of motorsport road racing which utilises sports cars that have two seats and enclosed wheels. They may be purpose-built prototypes or grand tourers based on road-going models. Broadly speaking, sports car racing is ...
, a technique known as ''slipstreaming'' is used. Along a long straight a car following close behind another uses the slipstream created by the lead car to close the gap between them, hoping to be able to overtake the leader under braking for the next corner, or if he has a straightline speed advantage, to pass on the straight. However it is very difficult for cars to follow each other close together in fast corners as the "dirty" (
turbulent
In fluid dynamics, turbulence or turbulent flow is fluid motion characterized by chaotic changes in pressure and flow velocity. It is in contrast to a laminar flow, which occurs when a fluid flows in parallel layers, with no disruption between t ...
) air that comes off the lead car unbalances the trailing car as its aerodynamic devices provide less grip. 4-time
Indianapolis 500
The Indianapolis 500, formally known as the Indianapolis 500-Mile Race, and commonly called the Indy 500, is an annual automobile race held at Indianapolis Motor Speedway (IMS) in Speedway, Indiana, United States, an enclave suburb of Indi ...
winner
Rick Mears
Rick Ravon Mears (born December 3, 1951) is a retired American race car driver. He is one of four men to win the Indianapolis 500 four times (1979, 1984, 1988, 1991) and is the current record-holder for pole positions in the race with six (1 ...
was quoted by motorsport.com writer David Malsher in 2015 as saying "The fact is, grip created by aerodynamic downforce is our enemy… At the moment, the downforce is so great that it masks the handling and hurts the racing."
Stock car racing
![Kyle leads the pack](https://upload.wikimedia.org/wikipedia/commons/8/8c/Kyle_leads_the_pack.jpg)
On the faster speedways and superspeedways used by
NASCAR
The National Association for Stock Car Auto Racing, LLC (NASCAR) is an American auto racing sanctioning and operating company that is best known for stock car racing. The privately owned company was founded by Bill France Sr. in 1948, and hi ...
and
ARCA, two or more vehicles can race faster when lined up front-to-rear than a single car can race alone. The low-pressure wake behind a group's leading car reduces the aerodynamic resistance on the front of the trailing car allowing the second car to pull closer. As the second car nears the first it pushes high-pressure air forward so less fast-moving air hits the lead car's spoiler. The result is less drag for both cars, allowing faster speeds.
[Lemasters, Ron Jr. (January 2001) "One Wild Wind", ''Stock Car Racing'' (ISSN 0734-7340), Volume 36, Number 1.]
Handling in corners is affected by balance changes caused by the draft: the leading car has normal front downforce but less rear downforce. The trailing car has less front downforce but normal rear downforce. A car with drafting partners both ahead and behind will lose downforce at both ends.
Similar to the "Belgian tourniquet" in cycling, the "slingshot pass" is the most dramatic and widely noted maneuver associated with drafting. A trailing car (perhaps pushed by a line of drafting cars) uses the lead car's wake to pull up with maximum momentum at the end of a straightaway, enters a turn high, and turns down across the lead car's wake. The combination of running downhill and running across the zone of lowest aerodynamic drag allows the trailing car to carry extra speed and pass on the inside of the leader.
Drafting was discovered by stock car racers in the
1960
It is also known as the "Year of Africa" because of major events—particularly the independence of seventeen African nations—that focused global attention on the continent and intensified feelings of Pan-Africanism.
Events
January
* Ja ...
Daytona 500
The Daytona 500 is a NASCAR Cup Series motor race held annually at Daytona International Speedway in Daytona Beach, Florida. It is the first of two Cup races held every year at Daytona, the second being the Coke Zero Sugar 400, and one of three ...
, when
Junior Johnson
Robert Glenn Johnson Jr. (June 28, 1931 – December 20, 2019), better known as Junior Johnson, was an American NASCAR driver of the 1950s and 1960s. He won 50 NASCAR races in his career before retiring in 1966. In the 1970s and 1980s, he became ...
found that he could use drafting as a strategy that helped him overcome the fact that his Chevrolet could not keep up with other cars, allowing him to win the race. Like Johnson, other drivers found they picked up speed running closely behind other cars; and as they experimented they found that a line of cars could sustain higher speeds and/or use less gas (resulting in fewer pit-stops) than a single car running by itself.
In recent years, as aerodynamics have become increasingly critical to the performance of stock cars on "intermediate" oval tracks (between 1.33 and 2 mi) and superspeedways not requiring restrictor plates (such as the
Indianapolis Motor Speedway
The Indianapolis Motor Speedway is an automobile racing circuit located in Speedway, Indiana, an enclave suburb of Indianapolis, Indiana. It is the home of the Indianapolis 500 and the Verizon 200, and and formerly the home of the United State ...
), the effect of turbulent, or "dirty" air when following closely behind another car has become much more akin to that described above in open-wheel racing (a situation described in NASCAR circles as ''aero push''), and is often cited as a main reason for a decrease in the amount of overtakes.
Bump drafting
Drafting is most important at NASCAR's
restrictor plate
A restrictor plate or air restrictor is a device installed at the intake of an engine to limit its power. This kind of system is occasionally used in road vehicles (e.g., motorcycles) for insurance purposes, but mainly in automobile racing, to li ...
tracks,
Talladega Superspeedway
Talladega Superspeedway, nicknamed “'Dega”, and formerly named Alabama International Motor Speedway (AIMS) from 1969 to 1989, is a motorsports complex located north of Talladega, Alabama. It is located on the former Anniston Air Force Base ...
and
Daytona International Speedway
Daytona International Speedway is a race track in Daytona Beach, Florida, United States. Since opening in 1959, it has been the home of the Daytona 500, the most prestigious race in NASCAR as well as its season opening event. In addition to NA ...
, where the plates mean that much less power is available to push the large bodies through the air. Race cars reach their highest speeds on these superspeedways, so the aerodynamic forces are highest, and the effects of drafting are strongest. Since restrictor plates were first used as a safety device, their effect has changed the nature of drafting. Vehicles no longer have sufficient horsepower or throttle response to maintain their drafting speeds upon exiting the draft; they can pull out and squeeze ahead but lack the response to clear the car being passed. This negates the slingshot maneuver. As a result, passing is often the result of cooperation between two or more drivers or is achieved by sucking air off the side of the car being passed, a technique called side-drafting.
Bump drafting is a tactic used at Talladega and Daytona. The technique was initially popularized by the Archer Brothers in the
SCCA
The Sports Car Club of America (SCCA) is a non-profit American automobile club and sanctioning body supporting road racing, rallying, and autocross in the United States. Formed in 1944, it runs many programs for both amateur and professional r ...
Sportruck series during the late 1980s.
[Glick, Shav (December 3, 1987), "Motor Racing", ''Los Angeles Times'', p. 10.] It begins as normal drafting, but the following car pulls up behind the lead car and bumps into the rear of it, pushing the lead car ahead, to maintain
momentum
In Newtonian mechanics, momentum (more specifically linear momentum or translational momentum) is the product of the mass and velocity of an object. It is a vector quantity, possessing a magnitude and a direction. If is an object's mass an ...
.
If done roughly or in the wrong position (e.g. close to the entry of the turn), this tactic can destabilize the handling of the lead car sometimes causing a crash. Use of the tactic in this manner is known as ''slam drafting''. Due to the danger, NASCAR has attempted to limit the bracing on bumpers on cars, disallowed bump drafting in turns, introduced "no bump zones" on certain portions of speedways where this practice is prevalent, and penalized drivers who are too rough in bump drafting. The 2010 NASCAR season allowed drivers more freedom; bump drafting was allowed anywhere, including turns.
Kyle Busch
Kyle Thomas Busch (born May 2, 1985) is an American professional stock car racing driver and team owner. He currently competes full-time in the NASCAR Cup Series, driving the No. 8 Chevrolet Camaro ZL1 for Richard Childress Racing and part-t ...
is largely responsible for a different type of bump drafting, which is now referred to as "two-car drafting" and "tandem drafting".
At a 2007 test session in Talladega, he asked
Ryan Newman to push him from behind, and was stunned to realize he was two seconds faster with Newman's help. At the newly paved
Daytona International Speedway
Daytona International Speedway is a race track in Daytona Beach, Florida, United States. Since opening in 1959, it has been the home of the Daytona 500, the most prestigious race in NASCAR as well as its season opening event. In addition to NA ...
in 2011, Busch was the first to realize that the corners were smooth enough to allow a two-car draft for the complete length of the track. During test sessions on the track, when Busch was pushed by his brother
Kurt's
Penske Racing
Team Penske (formerly Penske Racing) is an American professional auto racing organization, competing in the NTT IndyCar Series, NASCAR Cup Series, and the FIA World Endurance Championship. Debuting at the 1966 24 Hours of Daytona, the organiza ...
teammate
Brad Keselowski
Bradley Aaron Keselowski (; born February 12, 1984) is an American professional stock car racing driver, team owner, and entrepreneur. He competes full-time in the NASCAR Cup Series, driving the No. 6 Ford Mustang for RFK Racing, a team he also ...
, they ran 15 mph faster than single cars. Other drivers quickly picked up on Busch's strategy, and the two-car draft dominated the
2011 Daytona 500 and
Budweiser Shootout
The Busch Light Clash is an annual pre-season NASCAR Cup Series exhibition event held in February before the season-opening Daytona 500. The event was held each year at Daytona International Speedway since the race's inception in 1979 until 20 ...
. This strategy had also been very prominent at Talladega. In 2011, two-car tandem drafting was used for the extent of the
Aaron's 499
The GEICO 500 is a NASCAR Cup Series stock car race held at the Talladega Superspeedway in Lincoln, Alabama. The race is usually held in April or May. The 1997 event stands as the fastest NASCAR race to date ever run with an average speed of ...
, with many drivers drafting their own teammates (e.g.,
Jimmie Johnson
Jimmie Kenneth Johnson (born September 17, 1975) is an American professional auto racing driver. A seven-time NASCAR Cup Series champion, he competes part-time in the series driving for Petty GMS Motorsports. Johnson's seven Cup championships, ...
and
Dale Earnhardt Jr.
Ralph Dale Earnhardt Jr. (born October 10, 1974) is an American semi-retired professional stock car racing driver, team owner, author, and an analyst for ''NASCAR on NBC''. He currently competes part-time in the NASCAR Xfinity Series, driving t ...
drafted together, as did
Jeff Gordon
Jeffery Michael Gordon (born August 4, 1971) is an American former professional stock car racing driver, who is the Vice Chairman for Hendrick Motorsports. He raced full-time from 1993 to 2015, driving the No. 24 Chevrolet for Hendrick M ...
and
Mark Martin
Mark Anthony Martin (born January 9, 1959) is a retired American stock car racing driver. He has the second most wins all time in what is now the Xfinity Series with 49. He scored 40 Cup Series wins. He finished second in the NASCAR Cup Series st ...
). For the 2012 season, the Sprint Cup series cars were modified in a way that made the tandem impossible, in order to return to pack racing. In 2014, bump drafting was banned by NASCAR in the
Nationwide Series
The NASCAR Xfinity Series (NXS) is a stock car racing series organized by NASCAR. It is promoted as NASCAR's second-tier circuit to the organization's top level Cup Series. NXS events are frequently held as a support race on the day prior to a ...
and
Camping World Truck Series
The NASCAR Craftsman Truck Series is a pickup truck racing series owned and operated by the National Association for Stock Car Auto Racing, and is the only series in NASCAR to race production pickup truck based stock cars. The series is one of th ...
. Tandem Drafting made a return when NASCAR removed the restrictor plate and replaced them with Tapered Spacers, and with the flat noses and bumpers of the modern Gen 6 cars, drivers could more easily tandem and gain speed, much like the early 2010s. After Ryan Newman's scary crash in the
2020 Daytona 500, NASCAR made efforts to change drafting at superspeedways, where less horsepower was used: the removal of aero ducts to eliminate tandem drafting and decrease closing rates, and a smaller throttle body to lower the amount of air into a racecar.
Tailgating and hypermiling
Some drivers have been known to draft behind other vehicles, particularly
tailgating
Tailgating is the action of a driver driving behind another vehicle while not leaving sufficient distance to stop without causing a collision if the vehicle in front stops suddenly.
The safe distance for following another vehicle varies depend ...
larger vehicles, to save fuel. For example,
hypermilers
Hypermiling is driving or flying a vehicle with techniques that maximize fuel efficiency. Those who use these techniques are called "hypermilers". In the case of cars, this is an extreme form of energy-efficient driving.
Hypermiling can be practi ...
using this technique can achieve 75
mpg or more (a 10% increase in efficiency of certain hybrid vehicles). Some sources say that the most common tailgating does not save gasoline even at freeway speeds because one is likely to accelerate and brake so frequently that any aerodynamic savings are lost through the brakes.
On the show ''
MythBusters
''MythBusters'' is a science entertainment television program, developed by Peter Rees and produced by Australia's Beyond Television Productions. The series premiered on the Discovery Channel on January 23, 2003. It was broadcast internatio ...
'', drafting behind an 18-wheeler truck was tested and results showed that traveling behind the truck increased overall mpg efficiency by 11%. Traveling behind the truck produced a 39% gain in efficiency. Additionally, on the same episode, Mythbusters demonstrated that it can be very dangerous for the following car if one of the truck's tires (or their
recaps)
delaminate, as the chunks of ejected rubber can be large enough to cause serious harm, even death, to a driver following too closely.
Drafters also face the danger that, if the vehicle in front stops suddenly, there is little time to react.
Platooning is under study as a means to get the benefit while also increasing safety.
Computer simulation of drafting
Computer simulation (
computational fluid dynamics
Computational fluid dynamics (CFD) is a branch of fluid mechanics that uses numerical analysis and data structures to analyze and solve problems that involve fluid flows. Computers are used to perform the calculations required to simulate th ...
or CFD) is increasingly being used to analyse drafting. It is important to understand the aerodynamic behaviour of a motor vehicle when drafting, for example if the rear car is too close to the front car, the air supply to its radiator will be reduced and there is a possibility of the engine overheating. Most motor sport aerodynamic analysis is performed using wind tunnel testing. This becomes difficult for drafting cases, if only because a very large wind tunnel is needed. CFD, a kind of virtual wind tunnel, is used by race teams to understand the car's performance while drafting.
Racing game
Racing games are a video game genre in which the player participates in a racing competition. They may be based on anything from real-world racing leagues to fantastical settings. They are distributed along a spectrum between more realistic rac ...
s such as most in the
Mario Kart
is a series of racing games developed and published by Nintendo. Players compete in go-kart races while using various power-up items. It features characters and courses from the ''Mario'' series as well as other gaming franchises such as ''T ...
series simulate it by giving the player a speed boost.
Drafting in nature
Animals have been observed to use true drafting behavior reminiscent of auto racing or cycling.
Caribbean spiny lobsters for example are known to migrate in close single-file formation "lobster trains".
Vortex surfing
Vortex
In fluid dynamics, a vortex ( : vortices or vortexes) is a region in a fluid in which the flow revolves around an axis line, which may be straight or curved. Vortices form in stirred fluids, and may be observed in smoke rings, whirlpools in th ...
surfing is a related phenomenon that is currently being investigated by the
US Air Force
The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Signal ...
to save fuel on long-distance flights. The idea is to fly aircraft in the upward part of the
wingtip vortex of a leading aircraft.
[ In 2003, NASA said one of its F/A-18 test aircraft had a 29% fuel savings by flying in the wingtip vortex of a ]DC-8
The Douglas DC-8 (sometimes McDonnell Douglas DC-8) is a long-range narrow-body airliner built by the American Douglas Aircraft Company.
After losing the May 1954 US Air Force tanker competition to the Boeing KC-135, Douglas announced in Ju ...
. The DC-8/F-18 flight was an exploratory investigation of large aircraft vortex-induced performance benefits on a fighter-type aircraft. The aircraft flew at 25,000 feet with a separation of about 200 feet nose-to-tail. The F/A-18 slowly moved in laterally to explore the vortex effects, NASA said at the time. The Air Force has also tested vortex surfing with C-17s using auto pilot
An autopilot is a system used to control the path of an aircraft, marine craft or spacecraft without requiring constant manual control by a human operator. Autopilots do not replace human operators. Instead, the autopilot assists the operator' ...
in 2012, and indicated a 10% fuel saving. Tests in 2013 produced even greater fuel savings.
Vortex surfing in nature
Cooperative fluid dynamics
In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids— liquids and gases. It has several subdisciplines, including ''aerodynamics'' (the study of air and other gases in motion) an ...
techniques like drafting are also found in nature. Flocks of geese
A goose (plural, : geese) is a bird of any of several waterfowl species in the family (biology), family Anatidae. This group comprises the genera ''Anser (bird), Anser'' (the grey geese and white geese) and ''Branta'' (the black geese). Some o ...
and some other birds fly in a V formation
A V formation is the symmetric V-shaped flight formation of flights of geese, swans, ducks, and other migratory birds, improving their energy efficiency. Usually, large birds fly in this formation since smaller birds create more complex wind c ...
because the wingtip vortices
Wingtip vortices are circular patterns of rotating air left behind a wing as it generates lift.Clancy, L.J., ''Aerodynamics'', section 5.14 One wingtip vortex trails from the tip of each wing. Wingtip vortices are sometimes named ''trailing'' ...
generated by the front bird will create up-wash circulations. The birds flying behind will receive lift force from these up-wash vortices. Thus other birds in the flock do not need to work as hard to achieve lift. Studies show that birds in a V formation place themselves roughly at the optimum distance predicted by simple aerodynamic theory."Drag Reduction from Formation Flight. Flying Aircraft in Bird-Like Formations Could Significantly Increase Range"
; Defense Technical Information Center; April 2002; Retrieved February 27, 2008
References
External links
{{DEFAULTSORT:Drafting (Aerodynamics)
Motorsport terminology
Road bicycle racing terminology