Hydraulic and Hydromorphology laboratory (HHLab)

The Hydraulic and Hydromorphology Laboratory (HHLab) is a  platform of 350 m²  that includes three physical models (built and equipped from 2013 to 2017).  This platform is dedicated to the study of physical processes associated with river flows or flows in a highly anthropized environment.

The three facilities are

  • A wide flume, 3 m-wide, 18 m-long, 80 cm-deep, with a fixed bed slope of 1/1000.
  • A tilting flume, 1 m-wide, 18 m-long, 80 cm-deep, with a maximum bed slope of 5 %.
  • An urban flood model (MURI), 5.4 m-long, 3.8 m-wide, with maximum slopes of 5 % in the longitudinal and transverse directions.

Characteristics of the physical models

  Wide flume Tilting flume MURI
Total length 18 m 18 m 5.4 m
Width 3 m 1 m 3.8 m
Height 80 cm 80 cm 15 cm
Inlet conditions 3 independant inlet tanks 1 inlet tank 1 to 9 inlet tanks
Maximum discharge

300 L.s-1 (75 L.s-1  + 150 L.s-1  + 75 L.s-1)

150 L.s-1 50 L.s-1 to be shared between 1 to 9 inlets
Outlet conditions 3 adjustable tail weirs 1 adjustable tail weir 3 adjustable tail weirs+ 3 outlet tanks
Maximum bed slope 1/1000 5/100 5/100 in both directions

Water and sediment supply

The two long flumes (wide and tilting) are supplied in in three different ways:

  1. Clean water can be supplied through a constant head water tower. The water is then recycled in a basement area.
  2. Sediment (diameter < 1 mm) laden water can also be supplied in a close loop. The water is recycled in another smaller basement area equipped with stirrer to homogenize the sediment concentration.
  3. Finally, it is possible to work in an open configuration for coarse sediment. The sediment settles in an intermediate tank. The flumes are fed in sediment independently of the water.

 The scheme below illustrated these different modes:

Instrumentation

Several sensors are deployed:

  • Ultrasound sensors to measure free-surface elevation (9 sensors, 3 up-stream, 3 downstream, 3 mobile),
  • Discharge measurements with an electromagnetic flowmeter at the entrance of the flume.
  • Velocity measurements (Pitot tube, Acoustic Doppler Velocimeter, and PIV systems).
  • Topographic measurements with a 2D laser scan (submillimetrical resolution, Scan-Control 2900-100)
  • Pictures.

These sensors are fixed to a motorized trolley and can be moved automatically.

Research subjects

We use these facilities to address multiple issues such as :

  • vegetated flows
  • shear flows (compound channels and mixing layers),
  • transverse waves in stationary flows,
  • urban floods,
  • interactions between sediments of different sizes,
  • alternated bars dynamics,
  • unsteady flows

Publications

PhD and HdR Theses

Articles

Wide flume

The ‘wide flume’ is a 3 m wide and 18 m long glassed-wall open-channel with a longitudinal bed slope of 1.1/1000. Depending on the studied research topic, this flume is used : with a compound open-channel configuration (central main channel with one or two adjacent floodplains), 18 m x 3 m with a non-compound open-channel …

Tilting flume

Caracteristics The tilting flume (18 m-long and 1 m-wide, with an adjustable slope between 0 to 5 %) car be supplied in clear water (maximum discharge of 150 L/s) or with a sediment-ladden flow (for sediments smaller than 1 mm diameter, with a maximum discharge of 110 L/s). Larger sediments (1 to 30 mm) can …

Urban flood model

Main characteristics The Urban Model for the Study of Flood Risk, called ‘MURI‘ ( Modèle Urbain pour l’Étude du Risque d’Inondation) was built in 2017.  MURI is a platform of 5.4 m x 3.8 m, which can be tilted from 0 to 5% in the longitudinal and transverse directions. MURI is supplied with water by …