Roughing up wings: A promising technique in laminar flow control
Junior Applied Mathematics Seminar, Imperial College London, October 2015
In 1903, the Wright brothers made the first powered flight, travelling 37 m at an altitude of 3 m; in 1909, Louis Blériot was the first man to fly across the English Channel in an aeroplane. Today, the Eurofighter Typhoon can fly at around 2,500 km/h and has a range of almost 4,000 km (the distance from London to Timbuktu, Mali): the modern aeroplanes that fill our skies look nothing like the flimsy structures of a little over a century ago.
One of the key areas of aerodynamics research is laminar flow control—the art of influencing the structure of a laminar boundary layer as it moves over a surface. Wilbur Wright stalled just after take off three days before Orville successfully flew: now, new and more effective techniques in laminar flow control to avoid stall and reduce drag are constantly being sought. The work of Huebsch, Rothmayer and others demonstrates the potential of small dynamic roughnesses for delaying or suppressing the separation of a laminar boundary layer from a surface. This talk will present their numerical and experimental results, as well as explaining why they’re so important.