Sci-tech Francis Turbine Operating Principles Model FM 96 is the model of a Francis turbine demonstrating the function of a reaction turbine.
Water turbines are turbomachines utilizing water power. The Francis turbine is a type of reaction turbine which converts the pressure energy of the water into kinetic energy in the control device and in the impeller. The water is fed in the control device by means of a spiral housing. The flowing water is accelerated in the control device by the adjustable guide vanes and directed onto the vanes of the impeller. The redirection and further acceleration of the water in the impeller generates an impulse which is transmitted to the impeller. The experimental unit consists of the impeller, the control device with adjustable guide vanes, a band brake for loading the turbine and a housing with a transparent front panel. The transparent cover enables to observe the water flow, the impeller and the guide vanes during operation. The angle of attack and thus the power of the impeller are modified by adjusting the guide vanes.
The turbine torque is determined by force measurement on a band brake and is read on spring balances. For measuring the rotational speed, a non-contact speed sensor, HM 082, is required. A manometer shows the water pressure at the turbine inlet.
The experimental unit is positioned easily and securely on the work surface of the HM 150 base module.
The water is supplied and the flow rate is measured. Alternatively, the experimental unit can be operated by the laboratory supply.
The well-structured instructional material sets out the fundamentals and provides a step-by-step guide through the experiments.
* Model of a reaction turbine
* Transparent operating area
* Turbine with adjustable guide vanes
* Loading by band brake
 function of a Francis turbine
 transparent front panel for observing the operating area
 loading the turbine by use of the band brake
 adjustable guide vanes for setting different angles of attack
 marking on brake drum for non-contact speed measurement
 instruments: spring balances for determining the torque, manometer shows pressure at turbine inlet
 flow determination by base module
 water supply using the base module or via lab supply
– output: 12W at n=1100min-1, approx. 40L/min,
– impeller, 7 vanes
vane width: 5mm
external diameter: 50mm
– guide vanes: 6 vanes, adjustable (20 stages)
– braking force (spring balance): 10N
– pressure: 0…1,0bar
List of Experiments
– design and function of a Francis turbine
– determination of torque, power and efficiency
– graphical representation of characteristic curves for torque, power and efficiency