Application of exact coherent structures to transition and turbulence

Recognition in the 1980s that apparently well-organised or coherent motions appear persistently in turbulent flows provided an insight which opened the possibility for understanding and control of such flows, but lacked a sound basis in theory. Recent work suggests that coherent structures in turbulence may be identified with nonlinear solutions of the exact equations of motion. Such "exact" coherent structures have their Reynolds number dependence described explicitly and apply for moderate to very large Reynolds numbers, well above the range of full Navier-Stokes calculations. The project aims are to deepen understanding of these structures and to devise methods to prevent bypass transition to turbulence and reduce turbulent wall drag.