Everyone expects a good political demonstration or two at next month’s Olympic Games in Beijing. Maybe even a drug or doping scandal. There may also be complaints about the environment. And, you can count on some controversy surrounding all the advanced technology at the Games.
Much of the attention—and tension—is expected to center on the “White Cube.” The drama in this spectacular swimming venue, which was designed and built for this year’s Olympics, will focus on the world’s top swimmers and their new Speedo LZR Racer swimsuits.
Speedo, the world’s largest swimsuit manufacturer, has adopted computational fluid dynamics (CFD) software to significantly reduce the drag and skin friction experienced by swimmers and compress their bodies into a more streamlined shape, enabling them to cut through the water with more power and agility (Fig. 1). CFD software is used in the aerospace and other industries as well as to simulate the performance of Formula One racecars and America’s Cup yachts.
Since the LZR Racer’s unveiling in February, swimmers wearing it have set a staggering 38 world records and renewed the debate over whether technology has too much influence over the sport (Fig. 2). Japanese swimmers set 17 new national records wearing the LZR suit in one weekend in mid-June.
“This is clear evidence of the power of applying advanced engineering simulation technology to optimize all of the design metrics of a product,” says Jim Cashman, president and CEO of Ansys Inc., which helped design the new suit. Alberto Castagnetti, Italy’s national swimming coach, though, compared wearing the new Speedo suit to “technological doping.”
Speedo had a lot of help designing the suit, primarily from Ansys, a simulation software specialist, and Aqualab, Speedo’s own in-house R&D group. But it also worked with researchers at the University of Otago in New Zealand, the University of Nottingham in the U.K., the Australian Institute of Sport, Optimal Solutions in the U.S., and NASA.
In a sport where hundredths of a second can mean a gold medal or no medal at all, the Speedo research team has cut the passive drag of the LZR Racer by 10% from the earlier Fastskin FSII model and by 38% over ordinary Lycra swimsuits still used by a few world-class swimmers.
GO WITH THE FLOW
Skin-drag is inherent in swimsuit fabrics, so work on the new suit, priced by Speedo at a hefty $290, started by identifying the most drag-resistant fabrics. Researchers also took body scans of over 400 elite swimmers to provide geometries for testing more than 100 different fabrics and suit designs.
To test the fabrics and create a suit with the least drag, they used water flumes at the University of Otago. NASA contributed by evaluating the surface friction of fabric candidates in its low-speed wind tunnel, operating at 28 meters per second to simulate swimmers moving at two meters per second in the water. NASA used an aluminum plate as a benchmark for the fabric tests.
Drag reductions identified in the water flume and wind tunnel translated to a 4% increase in speed for swimmers when wearing the new suit as opposed to wearing their regular training swimwear. The new suit even improved the swimmers’ oxygen utilization by 5% compared to the training wear.
Ansys focused its work on the passive drag of the suit design, which occurs when the body is in the glide position with arms outstretched in front and legs outstretched behind. Swimmers maintain this position for up to 15 meters immediately after diving and for a similar distance after kicking off underwater after each turn. CFD analysis by Ansys identified areas in which both skin-drag and form-drag occur.
The CFD simulations involved precise boundary-layer meshing techniques using software from Ansys and resolved fine fluid flow details using the precision-scanned geometries of elite swimmers. Armed with detailed fluid dynamics data from the CFD studies, Speedo and Ansys guided the final design of the new suit, such as the precise location of the ultra-low-drag LZR panels bonded onto the suit. The placement of the panels reduced skin-drag by 24% compared to Speedo’s Fastskin fabric suit.
Keith Hanna of Ansys, who lectures on the application of CFD technology in sports, says a big development could come from the use of comprehensive multiphysics technology for elite swimsuit design. That would mean using CFD with other physics, such as structural simulation, to simulate every aspect of real-world physics in a competitive scenario.
While Speedo and its worldclass swimming customers are raking in the gold, it’s not clear if Speedo has any competition. Japanese swimwear manufacturers launched an effort to prevent the country’s athletes from defecting to Speedo for the Beijing Games. In May, Mizuno, Descente, and Asics unveiled their own hastily designed hightech suits they hope will hold up competitively.
At the same time, privately held TYR Sport Inc., the second largest swimwear maker, filed suit against No. 1, the unit of the Warnaco Group that makes Speedo swimsuits. TYR alleges violations of federal and state antitrust laws, restraint of trade, and false advertising in connection with Speedo’s new suit.
TYR also sued USA Swimming, the sport’s national governing body, and its head coach, Mark Schubert, who allegedly told U.S. Olympic team hopefuls that they had better wear Speedo at this summer’s team trials for the Beijing Olympics “or they may end up at home watching on NBC.” The Japanese Swimming Federation resolved the issue for its swimmers in June when it said it would not require its athletes to wear the approved Mizuno, Descente, and Asics suits and that they could switch to the LZR suit.
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Speedo isn’t the only one taking an interest in CFD. Engineers are using CFD and a spreadsheet model to redesign oar blades for Olympic rowing events. The technology also has been applied systematically in cycling for everything from bicycle aerodynamics to helmet design and the cyclist’s posture.
But there’s still some debate among cyclists when it comes to what kind of rear wheel performs best in a crosswind. While disk wheels have been known to become unmanageable for the front wheel of a cycle on windy days, it’s still a toss-up among cyclists between disk or spoked wheels for the rear.
Some cyclists are convinced that rear disk wheels act as a sail in certain circumstances, providing a forward force in the direction opposed to the drag force, reducing the net drag experienced by the cyclist (see the table). Cycling coaches and their advisers are still using CFD to develop more information on cyclists’ form drag, skin frictional drag, and cyclist/bike interaction effects—data not easily obtained from windtunnel tests.
Timing is everything in the Olympics. Omega, which first began timing Olympic Games events in Los Angeles in 1932 when handheld stopwatches were used, will play a big role in this year’s Games.
About 400 professional timekeepers and 1000 volunteers will be responsible for timing performances in China, using three timing systems for most events—the main system and two backups. And, like Speedo’s LZR swimsuit, timing the swimming events at the Beijing Games has created some controversy of its own.
Omega developed a set of starting blocks for swimmers for the Beijing Games. Its angled “wedge” at the rear of the platform resembles a starting block used in track competition—accommodating the “one foot forward, one foot back” starting style adopted by most top swimmers today (Fig. 3). The blocks are expected to improve race times by as much as one-tenth of second—a huge leap by world-class swimming standards.
The new blocks have won support from the International Swimming Federation, and Omega has set up a prototype of the block in lane nine of the new pool in Beijing. But Australian swimming officials, along with their colleagues from other countries, complained that swimmers likely to qualify for their countries’ Olympic teams will not have enough opportunity to practice with the new starting blocks.
The coaches won their argument. The Federation Internationale de Natation (FINA), the world swimming body, has decided to delay the use of the new Omega starting blocks until after the Beijing Games. The new blocks are expected to be used for the first time in major competition in September at the World Cup Competitions and the 2009 World Championships.
In track, runners’ starting blocks are equipped with a loudspeaker linked to the starter’s pistol so all contestants hear the start signal at precisely the same time (Fig. 4). A false-start detection system built into the starting blocks measures each runner’s reaction time, defined as the interval between the sound of the starter’s pistol and the athlete’s response.
The sensors built into the starting blocks detect each runner’s response to the sound of the starter’s pistol (pressure exerted by the athlete’s foot against the blocks). If the time measured is less than the time in which a person can possibly react to the sound of the starter’s gun, the runner has “jumped the gun,” and the timekeeper signals a false start.
For swimming events, the well-known touchpad immersed at the end of each lane allows each swimmer to “stop” the clock simply by touching the pad (Fig. 5). As a backup for judges, a high-speed video camera records the end of every swimming race.
Omega also will use a “virtual record line” that enables television broadcasters to electronically superimpose a red line across the pool. The line advances at the world record pace for each event. A swimmer finishing ahead of the red line indicates a new world record has been set.
A new video replay system from Omega for the swimming events will check on the legality of starts, finishes, and relay changeovers. The old system used videotape that could be rewound and reviewed only following the race, leading to delays in determining the results of races. The new digital system can be checked while the race is in progress so results can be confirmed immediately.
Another recent development by Omega provides live timing of swimming events. Anyone with Internet access can view swimming and diving competition results in real time on the Omega Timing Internet site at www.omegatiming.com.
Omega also has a foothold in the men’s and women’s marathons with its development of a new timing feature for this year’s Games. The company will equip runners with a radio-frequency identification (RFID) transponder attached to a shoe before the race. During the race, the runners will pass a series of antennas installed along the course, transmitting a personal ID code to an Omega receiver. This will enable Omega to record each runner’s time at specific intervals of the race.
GPS will also be used during the marathon for real-time mapping. A GPS transmitter will be installed in a car traveling just ahead of the lead runner, allowing timekeepers to know precisely how far along the course the leaders have advanced.
And, GPS will be used to reduce the confusion of spectators who have problems keeping track of what’s going on during sailing events—like who’s winning (Fig. 6). Omega will use GPS to relay information to viewers, showing each boat’s position. Omega is taking a similar tack in rowing, where timers will accurately position the competitors to determine if one boat is catching another and whether it might do so before the finish line.
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LOTS OF VIDEO
Video analysis, which is critical at the world-class level, is being heavily employed in the run-up to the Olympics. In fact, national coaches of U.S. teams and specialists in video analysis have conducted performance technology workshops for seven years, mostly at the U.S. Olympic Training Complex in Colorado Springs.
More recent working sessions used a system developed by Dartfish USA Inc., mostly to record precision comparisons and contrasts of performances. Almost all Olympic athletes, including those in track and field, gymnastics, softball, and taekwondo, are going with Dartfish technology. “This tool will help take taekwondo to the next level,” says U.S. men’s head coach Jean Lopez. “It’s a great tool for instant feedback and in scouting opponents.”
Using the Dartfish system, athletes are filmed with a digital camera—typically by a coach—and the film is fed into computers for picture-by-picture analysis. Sequences can be overlaid with reference film to show differences in performance.
Swimming coaches have also been using underwater cameras to record swimmers being towed through the water to test slightly different body positions to minimize drag and improve speed. Another visual technique is to have kayakers use special training goggles to show their vital statistics in real time as they’re training, including heart-rate data.
AND THE 2012 GAMES?
London officials have already said they expect the cost of staging the 2012 Olympic Games at about $3.7 billion, higher than their previous estimate of $2.8 billion.
Will there be “faster” swimsuits in the 2012 Olympic Games? Speedo and its competition are working on it. Will the new Omega starting blocks for swimmers that got nixed for this year’s Games be used in 2012? We’ll probably see something even better.
Swimmers are already improving their form with software from the University of Edinburgh’s Centre for Aquatics Research and Education. The software provides instant and detailed feedback on a swimmer’s glide technique and even suggests ways swimmers can improve their posture to help reduce drag.
Swimmers are marked on their body joints using water-resistant markers. Underwater video cameras record them swimming, and the images are fed into a computer that tracks the markers through the water. The image is overwritten with graphs and charts indicating where improvements are possible.
Aside from the competition, Texas Instruments has already produced a white paper that looks at the 2012 Olympic Games, called “The Wireless World in 2012: A Day at the London Olympics 2012.” It’s authored by TI’s Alan Gatherer, chief technology officer for Communications Infrastructure, and Sandeep Kumar, strategic marketing manager, Communications Infrastructure.
Gatherer and Kumar believe technical issues that seem daunting now will likely be resolved by 2012. Even more interesting, they say in their paper, will be the changes that occur in business models as channel bandwidths increase in scale and more content providers have ready access to them.
The most significant change to the wireless network at the 2012 Olympics will be the merger of voice-centric cellular with circuit-switched delivery in real time, and data-centric wireless local-area networks (WLANs) with IP-based packet-switched delivery into a single data network.
With that at least as a starting point, Gatherer and Kumar see attendees of the London Games using 4G cell phones and PDAs for just about everything, including finding their way through the London traffic, security alerts, and accessing local wireless networks for closeups and replays of Olympic events streamed to their mobile devices.
“Eventually, all air interfaces will support general voice, video and data applications,” TI says. “Range, bandwidth, and available service offerings will make the difference as to which type of network works best for a specific use. The networks probably won’t be fully merged by 2012, but they will be well on their way.”
With all of the security anticipated during the Beijing Olympics, technology four years from now will make the London Games a different experience. There will be entirely new ticketing and ID systems for officials, athletes, and spectators, possibly using a mobile authentication system developed by Nokia, and it may be the first cashless Olympics.
Still, Andrea Simmons, a member of the British Computer Society’s security group, has already expressed concerns in interviews with the British Broadcasting Corp. (BBC) that there has not been enough open discussion about what technology will be needed for the London Games in 2012.
The London Games may also provide an opportunity to build a stadium from the ground up, designed with the athletes’ performance in mind. CFD simulations of new sports stadiums are being built to determine how earthquake-proof they are, and how to improve heating and air-conditioning systems.
This resembles the work of Olof Granlund Oy, Finland’s leading building services consulting firm, when it designed new indoor ice hockey arenas in Russia. In fact, Ansys software was used on a nonlinear analysis of the pre-stressed truss shell roof structure of the Beijing Table Tennis Arena. This hybrid tension structure was assessed for pre-stresses, nonlinear buckling, and the roof ’s ultimate bearing capacity.
The next step, Ansys believes, may be to design sports arenas that consider how air flowing through a stadium affects the actual performance of the athletes, such as javelin and discus throwers, and even runners.
“In the next 10 years, CAE and multiphysics design tools will likely become one of a number of staple products used to design and construct better, more innovative and impactful sports stadiums around the world,” says Keith Hanna, Ansys’ European marketing director. “Advances in computer hardware and software will make engineers’ lives easier.”
Hanna also expects CFD to develop further, providing a greater understanding of the underlying fundamental flow and transport phenomena going on in most sports in real-world, real-time, complex, thermal, and multiphase situations.