Instrumentation

For wave observations

  • a set of capacitance wave gauges made of very thin sensitive wires, to measure water surface displacements with a great precision ( 0.01 mm) up to a frequency of 50 Hz,
  • a set of resistive wave gauges to measure water surface displacements with a precision of 0.1 mm up to a frequency of 12 Hz (Figure 11a),
    JPEG - 5.2 Mo
    Figure 11a

    Typical experimental setup with several wave gauges and anemometers.

    Crédit : D. Eeltink
  • a single-point laser slope gauge to measure both components of surface wave slope up to 45 ° to the horizontal plane (Figure 11c),
    JPEG - 3.3 Mo
    Figure 11c - Pictures of typical experimental arrangements

    Backscatter radar signature and wave slope measurements of paddle waves

    Crédit : G. Caulliez
  • a two-component wave slope imaging system composed of a two-color underwater lighting box of sizes 0.9x0.9 m2 and a high-resolution 3-color CCD camera (1920x1200 pixels up to 128 Hz), to investigate tridimensional wave patterns and space-time wave dynamics (Figures 9a & 9b),
    Figure 09a
    Sequences of images captured by the camera of the two-component wave slope imaging system, the fetch and wind conditions being respectively - X = 6 m – U = 6 m/s.
    R. Chemin
    Figure 09b
    Sequences of images captured by the camera of the two-component wave slope imaging system, the fetch and wind conditions being respectively - X = 26 m – U = 10 m/s.
    R. Chemin
  • video cameras for surface wave profiling and bubble visualizations ;

For air flow measurements :

  • one-, two- and three components hot wire anemometers to measure mean flow and turbulence characteristics throughout the air surface boundary layer,
  • two rigid hot-film transmitters to monitor air-flow velocity at a sampling rate of 2 Hz (Alliance Technology),
  • a two-component sonic anemometer (GILL MaxiMet GMX station),
  • a two-component Particle Image Velocimeter equiped with an 7 mirrors optical arm (Dantec Dynamics, 2x200 mJ, 532nm, 15Hz, 2048x2048 pixels flowsense camera),
  • a set of Pitot tubes and pressure transducers to measure mean air flow velocity,
  • thermistances and cold wire temperature sensors ;

For water flow measurements :

  • one- and two-component hot film velocimeters to investigate the water flow velocity field,
  • a three-component profiling Acoustic Doppler Velocimeter (Nortek Vectrino II) to explore the water velocity field over a 35 mm long distance, with a spatial resolution of 1 mm and a sample rate up to 100 Hz (Figure 11e) ;
    JPEG - 1 Mo
    Figure 11e

    Head of the three-component acoustic Doppler velocimeter (Nortek Vectrino II) set up for measurements of subsurface water flow at very low wind speed.

    Crédit : G. Caulliez
  • a three-component Acoustic Doppler Velocimeter (Sontek Micro ADV) to measure water flow characteristics at a single point with a sample rate up to 25 Hz ;
  • a piezo-electric pressure transmitter (Keller PR46X) to monitor water surface height variations ;

For other measurements :

  • one 3D multi-targets positioning system by means of 6 infrared cameras (spatial resolution of 1 mm in a 1 m3 volume) (Figure 11j),
    JPEG - 2.1 Mo
    Figure 11j

    Array of six infrared cameras for tracking of 3D target motions.

    Crédit : H. Branger
  • one Ku-band (13.5 GHz) scatterometer (Figure 11d),
    JPEG - 1.6 Mo
    Figure 11d

    Ku-band bistatic scatterometer.

    Crédit : J.P. Giovanangeli
  • one AMTI 6-dof sensor to measure the three components of moment Mx, My, Mz (scale of 5 Nm or 56 Nm), and force Fx, Fy, Fz (scales of 220 N or 2200 N max),
  • one Deltalab 2-dof sensor to measure the two horizontal components of force Fx and Fy (40 N max),
  • one digital one-dimensional Sauter dynamometer (50 N max),
  • a set of linear displacement systems to adjust probe location,
  • PC-based softwares for data acquisition and time series analysis (NI, Labview and Matlab).