Drafting (aerodynamics)
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.
Nike worked with the aerodynamics expert Robby Ketchell at the University of New Hampshire to experiment with and select a formation of pacemakers that would best minimize drag on the professionals it sponsored in the project it termed Breaking2.
A Wired magazine 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.
[3] Similar to the "Belgian tourniquet" in cycling, the "slingshot pass" is the most dramatic and widely noted maneuver associated with drafting.
[3] 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 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.
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.
At the newly paved Daytona International Speedway 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 teammate Brad Keselowski, 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.
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.
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.
[13] Drafters also face the danger that, if the vehicle in front stops suddenly, there is little time to react.
CFD, a kind of virtual wind tunnel, is used by race teams to understand the car's performance while drafting.
Racing games, such as most in the Mario Kart series, simulate drafting by giving the player a speed boost.
[14][15] Vortex surfing is a related phenomenon that is currently being investigated by the US Air Force to save fuel on long-distance flights.
Studies show that birds in a V formation place themselves roughly at the optimum distance predicted by simple aerodynamic theory.
