Leaning Forward: Speed, Inclination, and Modulation of Coherent Structures in Turbulence

Abstract: Coherent large scale motions contain the majority of the energy in wall-bounded turbulent flows and exert an important organizing influence on small scales. In this talk, I will discuss how fast these large scale motions convect, how the convection velocities are related to the inclination angle of these structures with respect to the wall, and why the convection velocity is important for modeling the interactions between large- and small-scale motions. The presentation will be based on experimental and computational measurements in turbulent wall-bounded flows, new analytical techniques for interpreting and modeling those measurements, along with some spectral theory, but should still be accessible to those interested in learning more about the basic problems of large-scale coherent motions in turbulence.