The Rayleigh-Taylor instability (RTI) is a buoyancy driven instability that takes place in a stratified fluid system with a constant acceleration directed from the heavy fluid into the light fluid in the presence of interfacial perturbations.
Incompressible Rayleigh-Taylor experiments are performed using a weight and pulley system to accelerate a test sled containing either miscible or immiscible fluid combinations. Interfacial perturbations are either left unforced, or are generated by vertical oscillation of the tank to produce Faraday waves. The unforced experiments rely on random interfacial fluctuations caused by background vibration to seed the instability. Accelerations of approximately 2g are experienced by the liquids, resulting in a net acceleration of 1g in the vertical direction. The tank is backlit and digitally recorded using a high speed video camera.
Rendering of the experimental setup
Accelerated test section
Tank and actuating system with voice coil and balance weights.
The Experimental Fluid Mechanics and Instability Laboratory
Aerospace and Mechanical Engineering Department at University of Arizona