November 23-25, 2025, Houston, Texas
Contributed Session

Flow Separation and Control

8:00 am – 10:49 am, Monday November 24 Session K32 George R. Brown Convention Center, 371CF
Chair:
Sidharth GS, Iowa State University
Topics:

Reverse Karman street via lock-in of a turbulent wake

9:31 am – 9:44 am
Presenter: Konstantinos Steiros (Imperial College London)
Author: Xiangyu Gao (Imperial College London)

It has long been long known that the periodic forcing of a bluff body wake can induce significant alterations to both the large-scale structures that are emanating from the body and to the mean-flow wake topology. These effects are greatly accentuated during ‘lock-in’, i.e. when the forcing frequency is made approximately equal to that of the naturally occurring vortex shedding instability.

Here, we present an experimental investigation of a turbulent wake lock-in via periodic oscillation of a solid plate. Our combined PIV and drag measurements show that, during lock-in, a drop in drag can be observed, associated with a reversal of the regular Karman street pattern.

Funding acknowledgement

ERC Starting Grant ONSET No. 101163321

PRESENTATIONS (13)