Objective identification of coherent vortices in turbulence using experimental data
Phys. Rev. Fluids 11, 034601 – Published 2 March, 2026
DOI: https://doi.org/10.1103/1tq2-pf6k
Abstract
Order within a chaotic system is crucial for understanding, predicting, and controlling the dynamics and statistics of the system. In this study, we propose an objective identification method of coherent vortices in turbulence, where we identify the axis of tubular vortices without any adjustable parameters. Since the only necessary quantity for this method is the velocity gradient tensor, we can easily apply it to experimental data. To demonstrate the capability of the proposed method, we conduct wind tunnel experiments of a turbulent boundary layer, optimized to extract the largest vortices. By combining the proposed method with the scale decomposition of the velocity gradient tensor, we show that many of the three-dimensional structures of the largest vortices in the flow are hairpin shaped.
