The facilities

The 30 m long, 3 m wide and 1.6 m deep water flume can operate with up to three layers of different densities (NaCl brines ranging from 1000 to 1200 kg/m3 monitored by computer), and velocities (ranging from 0.03 to 0.75 m/s). The temperature stability at 20 °C is ± 0.2 °C. The flume can also be operated as a towing tank filled with water for homogeneous flows or with stable density-stratified brines of any profile. The towing speed ranges from 0.08 to 0.50 m.s-1. Large and heavy obstacles are easily towed and the instrumentation can be transported on the carriage.

The channel in the circulation mode
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Gilles Orain - Météo-France
The channel in the towing tank configuration
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Gilles Orain - Météo-France

The laboratory also includes two smaller water tanks (7.0 x 0.6 x 0.6 m3 and 4.0 x 0.5 x 0.5 m3) that can be used for low Reynolds number tests as well as a small rotating turntable with a 1.6 x 1.6 x 1.2 m3 tank to study the effect of rotation on stratified or non-stratified flows.

State-of-the-art flow measurement techniques are available, including Laser Doppler Anemometer (LDA), hot-wire anemometry, fast conductimeters, Particle Image Velocimetry (PIV) and Laser-Induced Fluorescence (LIF). The laboratory has expertise in numerical simulations and may provide support for complementary numerical simulations.

POTENTIAL APPLICATIONS

The large density-stratified water flume is ideally suited to study geophysical and environmental flows at large Reynolds numbers. Among the flows that can be studied are:

· stratified flows such as stratified turbulence, vortices, internal waves, wakes and topographic flows; · stratified mixing layers; · atmospheric and oceanic boundary layers; · flow over flat or complex terrain; · other neutral or stably stratified flows, single or multi-layered; · free-surface flows.

Among the more recent studies are vortices and wakes in stably stratified environments, topographic wave-breaking, and boundary layers on rough surfaces.