Work

Simultaneous optical velocity and density measurements of resonant nonlinear internal waves in pycnocline

Year: 2025

Type: article

Abstract: We report on an experimental study of two-dimensional resonant internal standing waves excited by an immersed oscillating cylinder in a narrow rectangular basin. The basin is filled by two miscible liquids of close densities separated by a thin pycnocline. Simultaneous measurements of both velocity components by Particle Image Velocimetry and of the density field Background-Oriented Schlieren revealed complex spatiotemporal structure of the internal wavefield; each temporal harmonic contains multiple coexisting spatial modes. The study emphasizes the contribution of the nonlinear effects. A theoretical model is suggested that guides the data analysis procedure developed to identify individual modes and to reveal interactions between them. The model reproduces adequately the decrease of about 10% in the amplitude of the density variation due to cubic nonlinearity.

Source: Physics of Fluids

DOI: 10.1063/5.0275821

Authors: S. Kalenko, E. Mogilevskiy, E. Zemach, L. Shemer

Institutions: Tel Aviv University, Soreq Nuclear Research Center, Sami Shamoon College of Engineering

Language: English

Topic: Fluid Dynamics and Turbulent Flows

Subfield: Computational Mechanics

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Funders: Israel Science Foundation, PAZY Foundation

Awards: G7544889815, G859391512