Open-Channel Isolated Lateral Cavity: A Comprehensive Review

This paper provides a review of experimental, numerical, and field investigations dedicated to the isolated open-channel lateral cavity located on one side of a unidirectional flow. This cavity serves as a natural or manufactured sheltered area, commonly referred to as a dead zone, and can be found in both riverine and coastal environments. Due to its relatively simplified configuration, the isolated open-channel lateral cavity is among the most frequent dead zones reproduced in laboratory experiments. A total of 50 papers were found. While few papers investigate a cavity with a realistic geometry, the majority reproduces it under simplified geometries, either experimentally or numerically. The three main topics covered by the research works correspond to: (1) the time-averaged and turbulent hydrodynamics both within the cavity and at the interface with the adjacent main stream, (2) the mass exchange between the cavity and the main stream through this interface, and (3) the oscillation of the free surface in the cavity. By compiling all available data sets, we assess the consistency of the results across studies and examine how fundamental characteristics of the flow (number of recirculation cells, mass exchange coefficient, Strouhal number, surface oscillation mode) depend on the governing nondimensional parameters. Finally, we outline key open questions and research gaps, highlighting topics that have been largely overlooked and deserve further investigation.