Principal Investigator: Prof. Parviz Moin, Stanford University
Co-Investigator: Prof Javier Jimenez, Universidad Politecnica de Madrid
Research Assistant: Guglielmo Scovazzi, Stanford University

Funded by the Office of Naval Research

Over the last few years, an increasing interest has been devoted to the very large scales in turbulent wall flows. Very few data (either experimental or numerical) are available for their study, mainly due to two aspects: on one hand, these structures arise at relatively high reynolds numbers, for which the cost of Direct Numerical Simulations is too high (in terms of time and memory requirements); on the other hand a lot of effort (especially from the experimental point of view) has previously been devoted to the understanding of the dynamics of the flow very close to the wall surfaces (the so-called viscous sublayer), where the very large scales are not present. Dimensional analysis applied to energy spectra of the so called logarithmic and wake regions of wall turbulent flow fields indicates that the very large structures might look like relatively long jets, surrounded by streamwise vortices. The research program involves their study, using Large Eddy Simulation tools, to better understand their dynamics and the ways in which their control can be efficiently realized. Immediate applications are noise/drag reduction for turbulent wall flows.