Control for Turbulent Drag Reduction by Wall-normal Blowing and Suction
Date:
Abstract: This study investigates the impact of wall-normal blowing and suction on turbulent drag in a turbulent channel flow. The research explores the effect of various parameters, eg, actuation frequency, wavenumber, and waveform types (such as standing and streamwise-traveling waves) on the turbulent kinetic energy (TKE). Numerical analysis indicates a decrease and increase of TKE, respectively, in the vicinity of the blowing and suction regions of the channel wall. Further examination of two-point velocity correlations reveal enhanced streamwise rolls coinciding with reduced drag. Subsequently, the study incorporates closed-loop control, simulating surface velocity akin to subsurface structures, eg, metamaterials responding to fluid forces at the channel wall. This will provide a foundation for modeling and identifying surface and subsurface feedback control methods that could potentially mitigate turbulent drag.
Citation: C. T. Lin*, V. Ramakrishnan, A. J. Goza, K. H. Matlack, H. J. Bae, “Control for Turbulent Drag Reduction by Wall-normal Blowing and Suction”, APS DFD 2024: 77th Annual Meeting of the Division of Fluid Dynamics, Salt Lake City, UT, November 24 - 26, 2024.