AUTHOR=Huang Yi , Fu Song 

TITLE=Reynolds Number Effects on the Drag Reduction With a Spanwise Traveling Wave of Blowing and Suction in Turbulent Channel Flows

JOURNAL=Aerospace Research Communications

VOLUME=1

YEAR=2024

URL=https://www.frontierspartnerships.org/journals/aerospace-research-communications/articles/10.3389/arc.2023.12272

DOI=10.3389/arc.2023.12272

ISSN=2813-6209

ABSTRACT=<p>Turbulent channel flows with <italic>Re</italic><sub><italic>τ</italic></sub> = 180 and <italic>Re</italic><sub><italic>τ</italic></sub> = 550 are controlled to reduce the drag with a spanwise traveling wave of the blowing and suction method. An oscillatory spanwise motion is generated with a periodically reversing propagation direction of the traveling wave, similarly as the wall oscillation. Direct numerical simulation (DNS) results show that this kind of blowing and suction control can achieve a drag reduction rate of 24.5% with <italic>Re</italic><sub><italic>τ</italic></sub> = 180, and 7.5% with <italic>Re</italic><sub><italic>τ</italic></sub> = 550. The reasons for the deterioration in drag reduction rates are thought to be the lift-up mechanism by the actuation through an asymptotic expansion method, and the controlled inner regions and small-scale structures having less significance when the Reynolds number is high.</p>