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Design and manufacture of equipment for engineering education and research. Constantly evolving for the growing demands of the engineering education sector.


Free and Forced Vortex

This equipment is designed to produce and measure the characteristics of free and forced vortices.

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F1-23 Free and Forced Vortices - Issue 19

This equipment is designed to produce and measure the characteristics of free and forced vortices.

Ordering Specification

  • Cylindrical vessel with four inlet/outlet ports to generate free and forced vortices
  • Three interchangeable orifices and paddle wheel to fit in base of tank
  • Measuring bridge with adjustable pointers and internal caliper to measure vortex dimensions
  • Pitot tubes for estimation of velocities in vortex
  • Quick-release fittings for easy connection to hydraulics bench
  • Educational software available as an option


The apparatus comprises a clear acrylic cylinder on a plinth designed to produce and measure free and forced vortices. The free vortex is generated by water discharging through an interchangeable orifice in the base of the cylinder, and the resulting profile is measured using a combined calliper and depth scale. The forced vortex is induced by a paddle in the base of the cylinder, which is rotated by jets of water. The profile of the forced vortex is determined using a series of depth gauges.

Velocity at any point in the free or forced vortices may be measured using the appropriate pitot tube supplied. Dye crystals (not supplied) may be used to demonstrate secondary flow at the base of the free vortex.

Technical Details

Item Value
Tank diameter: 245mm
Height to overflow point: 180mm
Orifice diameters: 8, 16 and 24mm
Forced vortex measuring probes
Distance from centre:
0, 30, 50, 70, 90 and 110mm
Pitot tubes having measuring
point (nose) at:
15, 25 and 30mm radius
Inlet tubes: 9 and 12.5mm diameter

Measurement & Visualisation Capabilities

  • Understanding the difference between free and forced vortices
  • Determining the surface profile of a forced vortex
  • Determining the surface profile and total head distribution of a free vortex
  • Visualisation of secondary flow in a free vortex


F1-10 Hydraulics Bench

Shipping Specification

Individual accessories on request.

Overall Dimensions

Height: 0.46m
Width: 0.60m
Depth: 0.50m