Experimental and numerical investigation of a density-driven instability during a horizontal miscible displacement

We performed an experimental and numerical investigation of a convective buoyancy-driven instability that arises during the injection denser miscible fluid into less dense one in rectilinear geometry. visualized using shadowgraph technique, we obtained quantitative information micro-Particle Image Velocimetry. Numerical simulations provided further insights three-dimensional (3D) velocity field. have shown only occurs above certain Péclet number, Pe, depending on Rayleigh, Ra, Schmidt, Sc, numbers. suggest scalings critical time, TC, dimensionless wavelength, λ/h, instability, both which increase with increasing Pe Ra. Finally, investigated interactions vortices each other geometry boundaries.