Vortex Appartus
- A low-voltage, variable-speed motor rotates the vessel about its vertical axis.
- A speed-control unit, sited away from the main apparatus, controls the speed of rotation.
- To produce a forced vortex, students add water to the rotating vessel until it is about half full.
- A forced vortex forms.
- The surface falls rapidly towards the centre and produces an air core.
- Students measure the surface profile using the traverse probe.
- The traverse probe can move both horizontally and vertically, and both axes have linear scales.
- Students can also measure distribution of total head by replacing the traverse probe with a Pitot tube.
- After a few minutes the vortex becomes constant, and students can measure the surface profile using the traverse probe.