Title: Shear stress and noise metric reduction using active vibration
Authors: Dawei Li; Jinhao Qiu; Hongli Ji; Rui Nie
Addresses: State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, 29# Yudao Street, Nanjing, China ' State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, 29# Yudao Street, Nanjing, China ' State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, 29# Yudao Street, Nanjing, China ' State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, 29# Yudao Street, Nanjing, China
Abstract: The effects of active vibrational surface on wall shear stress and noise metric have been researched by the computational fluid dynamics method. The skin-friction drag and noise metric can be decreased by the active surface control. A sinusoidal vibration was imposed on the surface of a plate and the vibrational position located on downstream of the plate leading edge. The turbulence boundary layer was fully developed at the vibrational position. The downstream skin-friction drag exhibited a strong dependence on the control parameters (oscillation frequency and amplitude). A reduction in the trailing edge noise was obtained by the increasing of vibrational frequency and the appropriate choosing of amplitude. The maximum reduction in local skin friction drag is 64.3%. The noise metric can be decreased by 37.9 dB. Comparing the near-wall flow structures with and without control, it can be found that the turbulent kinetic energy and characteristic turbulence length scale were changed by the control.
Keywords: skin friction drag; turbulent kinetic energy; noise reduction; TBL; turbulence boundary layer; oscillation frequency; amplitude; computational fluid dynamics; CFD; wall shear stress; active vibration; active surface control; trailing edge noise; turbulent kinetic energy; turbulence length scale.
Progress in Computational Fluid Dynamics, An International Journal, 2016 Vol.16 No.5, pp.322 - 333
Received: 22 Sep 2014
Accepted: 22 Mar 2015
Published online: 02 Sep 2016 *