Stability of the Lid-Cavity Flow at Low Reynolds Numbers

The present work is concerned with the experimental study and numerical modelling of the 3D unsteady lid-cavity flow of stratified viscous fluids at very low Reynolds numbers. The main goal of the paper is to investigate the dynamics and the stability of the flow pattern under controlled perturbations induced by the variation of the driven velocity. The flow visualizations were performed in an open planar channel where a broad - crested weir with a center square cavity was placed on its bottom. The numerical simulations are performed in 3D flow configurations with the laminar unsteady solvers implemented in ANSYS Fluent 2021R1. The interface between two fluids is calculated with the VoF (Volume of Fluid) method, the densities distributions in the cavity being represented before and after the cessation of the induced perturbations.