Drag Reduction and Energy Saving by Spanwise Traveling Transversal Surface Waves for Flat Plate Flow

Flow Turbulence and Combustion, vol. 105, pp. 125–157

Abstract

Abstract Wall-resolved large-eddy simulations are performed to study the impact of spanwise traveling transversal surface waves in zero-pressure gradient turbulent boundary layer flow. Eighty variations of wavelength, period, and amplitude of the space- and time-dependent sinusoidal wall motion are considered for a boundary layer at a momentum thickness based Reynolds number of $${\rm Re}_\theta = 1000$$ Reθ=1000 . The results show a strong decrease of friction drag of up to $$26\%$$ 26% and considerable net power saving of up to $$10\%$$ 10% . However, the highest net power saving does not occur at the maximum drag reduction. The drag reduction is modeled as a function of the actuation parameters by support vector regression using the LES data. A dependence of the spanwise pressure drag on the wavelength is found. A substantial attenuation of the near-wall turbulence intensity and especially a weakening of the near-wall velocity streaks are observed. Similarities between the current actuation technique and the method of a spanwise oscillating wall without any normal surface deflection are reported. In particular, the generation of a directional spanwise oscillating Stokes layer is found to be related to skin-friction reduction.

Authors 6

1. Marian Albers corresponding Aachen Institute of Aerodynamics

   RWTH Aachen University

   Affiliation as printed

   Institute of Aerodynamics, RWTH Aachen University, Aachen, Germany

   RWTH Aachen University

2. Pascal S. Meysonnat Aachen Institute of Aerodynamics

   RWTH Aachen University

   Affiliation as printed

   Institute of Aerodynamics, RWTH Aachen University, Aachen, Germany

   Institute of Aerodynamics, RWTH Aachen University,#N#Aachen, Germany

3. Daniel Fernex

   Technische Universität Braunschweig

   Affiliation as printed

   Institut für Strömungsmechanik, Technische Universität Braunschweig, Braunschweig, Germany

4. Richard Semaan

   Technische Universität Braunschweig

   Affiliation as printed

   Institut für Strömungsmechanik, Technische Universität Braunschweig, Braunschweig, Germany

5. Bernd R. Noack

   Centre National de la Recherche Scientifique · Université Paris-Saclay · Technische Universität Berlin · Technische Universität Braunschweig · Harbin Institute of Technology · Laboratoire d'Informatique pour la Mécanique et les Sciences de l'Ingénieur

   Affiliation as printed

   Institut für Strömungsmechanik und Technische Akustik (ISTA), Technische Universität Berlin, Berlin, Germany

   Institut für Strömungsmechanik, Technische Universität Braunschweig, Braunschweig, Germany

   Institute for Turbulence-Noise-Vibration Interaction and Control, Harbin Institute of Technology, Shenzhen, China

   LIMSI, CNRS, Université Paris-Saclay, Orsay, France

6. Wolfgang Schröder Aachen JARA Center for Simulation and Data Science Institute of Aerodynamics

   RWTH Aachen University

   Affiliation as printed

   Institute of Aerodynamics, RWTH Aachen University, Aachen, Germany

   JARA Center for Simulation and Data Science, RWTH Aachen University, Aachen, Germany