Increased Efficiency from Tubercles-Shaped Wind Turbines
Who would have thought that whales could help solve the world?s energy crisis? Actually, they can?t?at least, not with the conventional source of energy used today. And more specifically, whale flippers are what have been pushing us into the world of limitless supplies of energy. Recently, Frank Fish, a biologist at West Chester University, and others have discovered a new way to design wind turbines that maximizes their efficiency in harnessing energy. These turbines are modeled after whale flippers, which turned out to have a much more clever design than scientists had ever thought.
Although wind turbines can potentially harness an abundance of energy, they are often not utilized because of their inefficiency under varying wind conditions. Under especially high or low rates of flow, the turbines may stall, or lose lift. In such cases, the wind?s angle of attack is greater than the stall angle, the maximum angle it can reach before the turbine stops under the increased drag and reduced lift. A normal wind turbine?s stall angle is usually very small, forcing it to operate within a narrow range of flow rates, because scientists chose stability over high-performance. Another reason why turbines are not commonly used is that they need to be built in open areas, which are decreasing in number with each passing year. Financially, the turbines are also costly to build. Due to these reasons, there has been little progress in wind power?until now.
When Frank Fish was observing the sculpture of a humpback whale, he noted that there were bumps on the flippers where there should not have been any. After all, if whales move as fast as they do in fluids, shouldn?t their flippers have a streamlined shape? The shopkeeper, however, assured him that the sculpture was accurate. After analyzing the fluid dynamics of the system, Fish and his colleagues conducted an experiment comparing a normal smooth airfoil, an object that produces lift as air flows past it, to an airfoil with small bumps along the edge, called tubercles. The results were surprising: the stall angle was pushed back from 16° for a normal airfoil to 31° for the new model, which means it can stably operate under a wider variety of wind conditions. Furthermore, when the model did stall, it stalled gradually, unlike other airfoils that stall so suddenly that the product can be damaged. Even better, the tubercle-lined airfoil is quieter than regular airfoils and use 20% less energy to achieve the same results.
Fish co-founded a company called WhalePower, dedicated to furthering the technology in wind power and other applications. The experiment was so successful that many companies have inquired about using WhalePower?s tubercle technology. The tubercle design can also be used to increase efficiency in ceiling fans, HVAC fans, hydroelectric turbines, and any other system that uses airfoils. Since wind energy is clean, renewable, and now efficient, tubercle technology will soon allow it to produce a significant portion of the world?s energy needs.
