Drag Reduction of Turbulent Boundary Layers by Travelling and Non-Travelling Waves of Spanwise Wall Oscillations
نویسندگان
چکیده
Turbulence control in the form of a streamwise travelling wave transverse wall motion was studied numerically by employing direct numerical simulations (DNS). Both total and phase averaging were utilised to examine statistical behaviour turbulence affected forcing, with focus on skin friction. Comparison results from pure temporal spatial forcing are conducted, compilation data is used explore analogies drag-reduced channel flow.
منابع مشابه
Turbulent Drag Reduction by Spanwise Wall Oscillations
The objective of this paper is to examine the effectiveness of wall oscillation as a control scheme of drag reduction. Two flow configurations are considered: constant flow rate and constant mean pressure gradient. The Navier-Stokes equations are solved using Fourier-Chebyshev spectral methods and the oscillation in sinusoidal form is enforced on the walls through boundary conditions for the sp...
متن کاملTurbulent Drag Reduction by Spanwise Wall Oscillations
The objective of this paper is to examine the effectiveness of wall oscillation as a control scheme of drag reduction. Two flow configurations are considered: constant flow rate and constant mean pressure gradient. The Navier-Stokes equations are solved using Fourier-Chebyshev spectral methods and the oscillation in sinusoidal form is enforced on the walls through boundary conditions for the sp...
متن کاملStreamwise-traveling waves of spanwise wall velocity for turbulent drag reduction
Waves of spanwise velocity imposed at the walls of a plane turbulent channel flow are studied by Direct Numerical Simulations. We consider sinusoidal waves of spanwise velocity which vary in time and are modulated in space along the streamwise direction. The phase speed may be null, positive or negative, so that the waves may be either stationary or traveling forward or backward in the directio...
متن کاملNumerical Studies of Active Control of Turbulent Boundary Layers Using Transverse Travelling Waves
Turbulence control in the form of transverse wall motion is employed numerically (direct numerical simulation). Results from a turbulent boundary layer subjected to spanwise wall forcing in the form of a streamwise travelling wave are presented for the first time. Both total and phase averaging have been utilized to examine the statistical behaviour of the turbulence affected by the wall forcin...
متن کاملDrag reduction in turbulent boundary layers by in-plane wall motion.
Drag-reduction techniques capable of reducing the level of turbulent friction through wall-parallel movement of the wall are described, with special emphasis placed on spanwise movement. The discussion is confined to active open-loop control strategies, although feedback control is briefly mentioned with regard to peculiarities of spanwise sensing and/or actuation. Theoretical considerations ar...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Fluids
سال: 2022
ISSN: ['2311-5521']
DOI: https://doi.org/10.3390/fluids7020065