Developed by Prof. Israel Wygnanski, Dr. Avi Seifert, and their students at TAU s Department of Fluid Mechanics and Heat Transfer, Fleischman Faculty of Enginnering, the technique re-energizes the sluggish boundary layer of air and in some cases forces the flow to reattach to the wing. The method involves mounting an electro-mechanical device inside the wing that blows pulses of air onto the surface of the wing. A combination of weak, steady blowing with strong periodic puffs creates vortices that mix the faster air current above with the slower air just below. The jolts of fast air stimulate the boundary layer and delay or even prevent its separation. Furthermore, tests conducted at the Illinois Institute of Technology at velocities of half the speed of sound indicate that the TAU method could increase the performance of airplanes and helicopters in high speed or maneuvering situations.
Flight tests are in progress.
NASA is also interested in the technology and experiments with the participation of the Israeli investigators are planned for 1997. The inclined line indicates the flap surface.