On the effects of energetic coherent motions on power and wake dynamics of an axial-flow marine turbine in an open channel

ORAL

Abstract

Laboratory experiments are carried out to study the effect of energetic coherent motions on the performance of a model axial-flow hydrokinetic turbine in the main channel at Saint Anthony Falls Laboratory. A mechanical system allows the turbine angular velocity to be precisely specified and maintained via a controller. Power fluctuations are tracked using a torque sensor connected to the turbine structure. Periodic energetic coherent motions are introduced in the flow by placing a cylinder at various locations upstream of the turbine on the plane of symmetry. Three acoustic Doppler velocimeters and a torque sensor are used to obtain synchronous high resolution measurements of the flow and turbine power at a rate of 200 Hz, respectively. Flow measurements are obtained at various locations upstream and downstream of the turbine. The measurements provide novel insights into the role of strong energetic coherent motions on turbine power fluctuations, tip vortex instability, and mean wake recovery. The implications of these findings for the efficient operation of hydrokinetic turbines in natural waterways will be discussed.

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Authors

  • Craig Hill

    University of Minnesota

  • Leonardo Chamorro

    U. of Minnesota, St. Anthony Falls Laboratory, Dep. Civil Engineering, UMN, University of Minnesota, U. of Minneasota

  • Vincent Neary

    Oak Ridge National Laboratory

  • Budi Gunawan

    Oak Ridge National Laboratory

  • Roger Arndt

    U. of Minnesota, University of Minnesota, U. of Minneasota, Saint Anthony Falls Laboratory - University of Minnesota

  • Fotis Sotiropoulos

    U. of Minnesota, University of Minnesota, U. of Minneasota, St. Anthony Falls Laboratory, Department of Civil Engineering, 2 Third Avenue SE, Minneapolis, MN 55414, USA, St. Anthony Falls Laboratory, University of Minnesota, St. Anthony Falls Laboratory, Department of Civil Engineering, University of Minnesota, 2 Third Avenue SE, Minneapolis, MN 55414, USA, Saint Anthony Falls Laboratory, University of Minnesota