Speed strips on oars

In Rio de Janeiro it will become apparent whether speed strips on oars can make the difference between winning and losing a race.

You may remember zigzag strips from the skating suits in Nagano (1998), where Dutch skaters won no less than eleven Olympic medals. Since then friction-reducing speed strips have appeared all over the place, including, since 2000, on oars. Although athletes and coaches are somewhat sceptical, the strips will nevertheless be used by the Dutch rowing teams in Rio. Two TU Delft  researchers and competition rowers have demonstrated that the strips really do make  a difference: a two-metre  lead for a single sculler on a two-thousand metre lane.

Master’s student Conno Kuyt and doctoral candidate Arnoud Greidanus presented their  research results at the eleventh conference of the International Sports Engineering Association that took place at TU Delft from 11 to 14 July. This study was led by Professor of Fluid Mechanics Jerry Westerweel (Faculty of 3mE). To be clear: this study focused on air friction caused by the oars, not on the friction of the hull moving through the water.

The effect of the zigzag strips is that they make the airflow along the oars turbulent, which reduces the suction effect behind the oar. This reduces air friction by approximately 1 percent. The air friction of the oars accounts for approximately 10 percent of the total friction affecting a single scull. This means that the strips represent an advantage of 0.1 percent. In a race of 400 seconds, this adds up to 0.4 seconds. If you believe this to be inconsequential, you do not understand much about top sport.

“I have been known to lose a race by 0.07 seconds,” says Greidanus. That was back at the 2012 World Championship in Plovdiv, where he and Joris Pijs only just missed the gold medal in their double scull. We know now that speed strips might have made all the difference.

Foto © Sam Rentmeester . 20160601 . Roeien - aerodynamische strips, Conno Kuyt, Arnoud Greidanus, Delft Integraal DI // thema

Photo © Sam Rentmeester

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