A 91-year-old towing basin hidden in a dark, secluded basement laboratory at the U-M could turn out to be one of the secret weapons behind a sleek, new racing yacht named Young America.
Designed and built by PACT 95a team of sailing enthusiasts and high-tech corporate sponsorsYoung America will compete in early 1995 for the honor of representing the United States in the May 1995 Americas Cup racethe most prestigious competition in international sailing.
When PACT 95 needed to determine the fastest and most efficient hull configuration for Young America, team member and U-M alumnus John Kuhn returned to the towing tank and faculty he worked with as an undergraduate in the Department of Naval Architecture and Marine Engineering.
U-M faculty and students have a great deal of expertise in seakeeping, or the knowledge of how ships perform in waves, Kuhn said. The towing tank in the U-M Marine Hydrodynamics Laboratory is one of the few places in the United States where it is possible to test prototypes under simulated wave conditions.
Built in 1903, the 12-foot-deep tank is longer than a football field. One end of the tank is equipped with an electrical wave-making machine and the other end has an artificial beach to absorb the impact of the waves. Scale models of boats are towed through the tank beneath a movable carriage, which is connected to a series of measuring devices. These sensors feed precise data on model velocity, forces and motions under a variety of wave conditions to a bank of computers for later analysis.
We are able to simulate wave conditions the boat could encounter during the race, said Stuart B. Cohen, director of the Marine Hydrodynamics Laboratory. About 70 wave tests are carried out for each hull form, added Guenther J. Kellner, engineering research assistant and lead test engineer.
Selecting the optimum design requires a tremendous amount of computational modeling, Kuhn explained. With data from towing tank measurements and computer programs developed by PACT 95 engineers to predict velocity, we are able to race two potential designs against one another on the computer and pick the fastest boat.
U-M undergraduate students and an Ann Arbor-area high school student helped collect towing tank data for PACT 95 during the project. We are pleased to have so much student involvement, because PACT 95 stresses the educational aspects of the Americas Cup race. Its a great way to get junior high and high school students interested in careers in science and engineering, Kuhn said.
Other members of the PACT 95 team who are U-M graduates include Bruce Nelson, principal designer, and Eric Schlageter, performance simulation
PACT 95, based in Bangor, Maine, is one of three defense syndicates competing for the honor of defending the Americas Cup in May 1995. It distinguishes itself from other syndicates through its Young America technology curriculum, which will be used in schools across the United States in the spring of 1995. PACT 95 also is producing a PBS mini-series on the sciences of the Americas Cup with Walter Cronkite as series commentator.