• How differently shaped weirs affect the flow.
  • Visualization of streamlines for flow incident to a weir.
  • Visualization of streamlines when flowing around various drag bodies.


  • Visualization of streamlines during incident flow and flow around various weirs and drag bodies
  • Transparent experimental flume
  • Incident flow demonstrated on two weirs
  • Demonstration of flow around four different drag bodies
  • Contrast medium: ink
  • Distributor for contrast medium with five nozzles
  • Water level in the experimental flume adjustable at the water inlet and weir at the (marbles) water outlet
  • Flow straightener for even, non-vortical water inlet
  • Water supply using Hydraulic Bench or via laboratory supply

Apparatus can be used to visualise flow around drag bodies and flow phenomena in open channels. Either a drag body or weir is fixed in the experimental flume. The streamlines are made visible by injecting a contrast medium. The experimental flume is made of transparent material so that the streamlines and the formation of vortices can easily be observed. The water level in the experimental flume can be adjusted. There is one weir and four different drag bodies available for the experiments. A stabilizer ensures an even and non-vortical flow of water. The experimental unit is positioned easily and securely on the work surface of the Hydraulic Bench or can be position on flat surface of lab with laboratory water supply and proper drain system. The water is supplied. Alternatively, the experimental unit can be operated by the laboratory supply.