68th Annual Meeting of the APS Division of Fluid Dynamics (November 22, 2015 — November 24, 2015)

P0047: Flow stabilization by crystals

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Authors

• Mahmoud I. Hussein, Department of Aerospace Engineering Sciences, University of Colorado Boulder
• Sedat Birigen, Department of Aerospace Engineering Sciences, University of Colorado Boulder
• Osama R. Bilal, Department of Aerospace Engineering Sciences, University of Colorado Boulder
• Alec Kucala, Department of Aerospace Engineering Sciences, University of Colorado Boulder

DOI: https://doi.org/10.1103/APS.DFD.2015.GFM.P0047

Flow control is a century-old problem in which the goal is to alter a flow's natural state to achieve improved performance, such as delay of laminar-to-turbulent transition or reduction of drag in a fully developed turbulent flow. Meeting this goal promises to significantly reduce the dependence of the world's population on fossil fuels for global transport. In this research, we propose a new concept for flow control whereby an enlarged and carefully tuned crystal is placed underneath a flexible surface exposed to the flow.  We show that vibrational motion of the crystal may be tuned to cause the flow to passively stabilize, or destabilize, as desired. This unprecedented fluid-structure interface wave synchronization capability enables favorable, and predictable, alterations to the flow properties with consequences on drag reduction for air, sea and land vehicles, wind turbines, long-range pipelines, as well as numerous other applications.