Drag-Reduction Effectiveness of Riblet Films in Adverse Pressure Gradients

ORAL

Abstract

Riblet films are micro-grooved structures that are widely known to passively reduce skin friction. Past studies have almost solely focused on riblet performance in channel-flows. However, possible applications of riblets include wind turbine blades, gas turbine blades, and other complex bodies that are exposed to non-zero pressure gradient flows---specifically adverse pressure gradients. We use high-resolution large eddy simulations of turbulent flow over three-dimensional riblets under an adverse pressure gradient. We analyze the computed results to quantify drag reduction effectiveness for different riblet shapes and to examine pertinent turbulent structures to gain a fundamental understanding of riblet performance.

*Supported by the DOE Wind Energy Consortium

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Authors

  • Aaron Boomsma

    • University of Minnesota

  • Fotis Sotiropoulos

    • University of Minnesota
    • St. Anthony Falls Laboratory, University of Minnesota, Minneapolis, USA
    • St. Anthony Falls Laboratory, University of Minnesota
    • St. Anthony Falls Lab., University of Minnesota
    • St. Anthony Falls Laboratory, Department of Civil Engineering, 2 Third Avenue SE, Minneapolis, MN 55414, USA
    • St. Anthony Falls Laboratory, College of Science and Engineering, Department of Civil Engineering, University of Minnesota
    • St. Anthony Falls Laboratory, Dept. of Civil Engineering, University of Minnesota
    • Saint Anthony Falls Laboratory, Civil Engineering, University of Minnesota