SCIENCE & ENGINEERING NEWS
Colorado Springs, COLO. — In the competitive world of swimming, nothing is too extreme to consider in efforts to shave fractions of a second off a swimmer’s finish time. So it should come as no surprise that shaved bodies and full body skinsuits have been joined by the latest computer technology. Aided by advanced modeling and simulation software, USA Swimming is designing and helping its elite swimmers achieve their perfect swim stroke.
USA Swimming, headquartered in Colorado Springs, Colorado, at the US Olympic Training Center, is the national governing body for the sport of competitive swimming in the United States. Until recently, USA Swimming’s research has been strictly experimental. Last year, USA Swimming became aware of groundbreaking research that was being done to analyze a swimmer’s strokes by Barry Bixler, Principal Engineer at Honeywell Engines and Systems, using computational fluid dynamics (CFD) software, which is used to analyze fluid flow.
What began as a hobby for Mr. Bixler has turned into extremely pertinent consulting research that is aiding USA Swimming to fine tune the strokes of their elite swimmers. Using software from industry leader Fluent Inc., Mr.
Bixler began running computer simulations of a swimmer’s hand and arm, altering certain variables, such as position of the hand and arm during a swim stroke and water turbulence. His preliminary CFD results compared well with traditional physical experimental data that had been arduously developed from a wind tunnel, a tow tank, and a flume.
Scott Riewald, Biomechanics Director of USA Swimming, states, “The sport of swimming has relied only on experimental research that has been done over the past 20 years. We wanted to take it to another level, and the technology behind CFD has allowed us to do just that. We recognized the potential in Barry’s work and have taken a very logical approach to gaining solid evidence that we know will help us settle the longest standing debate in the swimming community-how a swimmer’s propulsion is generated. Not only will Barry’s work allow us to analyze conditions, such as acceleration, deceleration and rotation of a swimmer’s stroke, that we could not have done experimentally, it has also allowed us to gain valuable data much more quickly and cost effectively,” Riewald concluded.
After joining forces with USA Swimming, Mr. Bixler’s research has progressed quickly. Through this research, Mr. Bixler has been able to establish a firm analytical foundation upon which to proceed with more complex analyses. His first project on research of a swimmer’s hand and arm is taking place in three phases. In Phase I, which took place last year, the hand/arm was analyzed in steady flow. Mr. Bixler’s main finding from this phase was that the aerodynamic efficiency of the hand is significantly less than an airfoil of similar aspect ratio.
Phase II, which has just been completed and was sponsored by the Sport Science and Technology division of the US Olympic Committee, analyzed the acceleration and deceleration of the hand/arm. Phase II results showed that drag and lift forces on the hand and arm are affected unequally by acceleration and deceleration. Phase III, which is planned for next year, will analyze the addition of rotation and direction change of the arm, making it possible to “design” the optimum stroke. Full body analysis is also planned as a separate project to begin in the near future, in conjunction with Phase III of the hand/arm.
According to Mr. Bixler, “Through this extensive research, I hope to demonstrate to the swimming community the benefits that can be achieved by gaining valuable information from such a simulation program. CFD is a tool that is just too powerful and useful to ignore, and fortunately, USA Swimming has chosen to lead the way in applying it to swimming. Ultimately, I hope to ‘design’ the optimum stroke which will improve elite swimmers’ performance.”
Mr. Bixler completed Phase I and II of the hand/arm analyses on an Intel Pentium III/667 DP Workstation. Intel Corp. has recently committed to provide Mr. Bixler with a parallel multiprocessor workstation to give him the computing power necessary to complete Phase III of the hand/arm analysis as well as for the full body analysis.
“The scalability of Intel Architecture enables threaded software such as Fluent to take advantage of multiple Intel processors,” said Raghu Murthi, Director of Marketing for Intel’s Enterprise Platform Group. “By using multiple Intel processors versus a single processor to perform its computations, Mr. Bixler can now achieve the computational performance necessary to continue using Fluent software to analyze complex data such as the dynamics of a swimmer’s stroke. This will provide him with the tools necessary to help the athletes excel.”
According to Keith Hanna, Director of Marketing Communications at Fluent, “While Barry’s research in the sport of swimming has never been done before, using this technology in sports engineering is not completely new. Fluent’s CFD software has been used by such recognized names in the world of sports as Team New Zealand to design the hull of their winning yacht in the 2000 America’s Cup, by Benetton Formula 1 and Team Rahal in designing their racecars, and by Quicksilver (WRS) Ltd. in designing their craft which will challenge the world water speed record in the winter of 2001/2002.
CFD has also been used to analyze the trajectories of a soccer ball to determine optimum ball design and to analyze the benefits of “V” style ski jumping vs. parallel ski jumping, just to name a few. The use of CFD in sports to help gain a competitive edge, through improved personal techniques or through better equipment design, is burgeoning,” Dr. Hanna concluded.
While Mr. Riewald and Mr. Bixler feel that it may be too early for Mr.
Bixler’s initial results from Phase I and II of the hand/arm analyses to affect the performance of the swimmers competing in the 2000 Olympics, both Mr. Riewald and Mr. Bixler are confident that this research will definitely have an impact on swimmers’ techniques and performance in their quest for “gold” at the 2004 Olympics.
USA Swimming, headquartered in Colorado Springs, Colorado, at the US Olympic Training Center, is the national governing body for the sport of competitive swimming in the United States. USA Swimming provides scientific support and training for US swimmers through the International Center for Aquatics Research and the Resident Team program. USA Swimming conducts internal research and supports outside research in the following areas: biomechanics, exercise physiology, and sports psychology. More information on USA Swimming is available at http://www.usa-swimming.org .
Fluent Inc. is a world leader in the rapidly growing field of computerized design and simulation software. Fluent’s software is used to predict fluid flow, heat and mass transfer, chemical reaction, and related phenomena.
Fluent’s software products and services help engineers in leading corporations world-wide with detailed product development, design optimization, trouble shooting, scale-up and retrofitting. Fluent’s software significantly reduces engineering cost, while improving the final design of products in applications ranging from design of electronic components and systems to automotive engineering, and from combustion system design to process plant troubleshooting. Additional information on Fluent’s products can be obtained on the World Wide Web at http://www.fluent.com .