Pascale Bouruet-Aubertot

A set of laboratory experiments in fluid dynamics with application to the ocean and the atmosphere are proposed for students in « licence » and « master ». The experiments are set up in room “TaTou” (for « Table Tournante ») at LOCEAN. The rotating table TaTou has a diameter of 80cm and a maximum rotation speed of 6 rad/s. A camera is embarked on the table and a quantitative analysis of experiments is conducted during practical classes and projects. The experiments are developed with the help of engineers from the marine technics team (DITM) of LOCEAN and are supported financially by IPSL and UPMC.

A set of examples

Gravity current:  the current is generated through the adjustement of a fresh water lens (dyed in red) over a salty water layer.  (movie) t

Geostrophic adjustment : a two-layer fluid (fresh/ salty water) is set-up within an inner cylinder, the establishment of a geostrophic current after the removal of the outer cylinder is studied. (movie)

geostrophic adjustment
Baroclinic instability: with the same set-up as the previous one but different parameter regime, baroclinic instability of the flow is evidenced. (movie) baroclinic instability
Thermal wind balance and baroclinic instability: a geostrophic flow is induced by an horizontal temperature gradient produced by the input of boiling water in a cylindrical metallic mug located at the center of the tank. (movie) thermal wind
Taylor column: the formation of a Taylor column above a cylindrical obstacle (2cm height) is induced by a small variation of the rotation speed of the tank and the evolution of the “outer flow” of  small Rossby number in the vicinity of the obstacle studied. Next a large Rossby number flow is induced for comparison with the previous case. (movie) Taylor column
Ekman transport in the bottom boundary layer: a cyclonic/ anticyclonic motion is induced by a variation of the angular velocity of the rotating table. The flow is visualized with potassium permanganate. (movie-cyclone,movie_anticyclone)

Solitary wave (movie): a solitary wave is generated by a density step within a two-layer fluid. The time-space evolution of the wave is analyzed and compared with that inferred from the resolution of KdV equation.
solitary wave
Double Diffusion (movie) We study the intrusions that developp when an ice block coloured with potassium permanganate melts into a stably stratified salt layer of warm water. The scaling of the intrusions is inferred, that depends the density gradient.
double diff