Wall Turbulence with Designer Properties: Identification, Characterization and Manipulation of Energy Pathways
Technical Report,01 Nov 2012,30 Nov 2015
California Institute of Technology Pasadena United States
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The research performed under this BRI award targeted the identification, characterization and manipulation of energy pathways in wall turbulence. The objectives were pursued separately and collaboratively by the California Institute of Technology Caltech, the University of Florida UF and the University of Texas at Austin UT teams through a joint numerical, experimental and modeling effort. Our approach applied the teams state-of-the-art capabilities in experiments Caltech, simulation UT, MEMS sensor development UF and linear algebra techniques Caltech to the resolvent formulation of the Navier-Stokes equations for wall turbulence proposed by McKeon and Sharma 2010. This formulation explicitly identifies the pathways for extraction of energy from the mean flow and transfer between wavenumbers, and thus can be used to identify forcing distributions required to manipulate the spectrum. Energetic pathways between modes have been identified, highlighted and characterized by experimentally exciting two modes and providing the first-known observation of a single triadic interaction.