Water turbines are turbomachines utilising water power. The Pelton turbine is a type of free-jet or impulse turbine; such turbines convert the pressure energy of water into kinetic energy entirely in the control device. During the conversion, the water jet is accelerated in a nozzle and directed onto the vanes of the impeller tangentially. The water jet is redirected by approximately 180° in the vanes. The impulse of the water jet is transmitted to the impeller. HM 150.19 is a model of a Pelton turbine demonstrating the function of an impulse turbine.
The experimental unit consists of the impeller, a needle nozzle used as control device, 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 nozzle during operation. You can modify the nozzle cross-section and thus the flow rate by adjusting the nozzle needle.
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, e.g. HM 082, is required. A manometer shows the water pressure at the turbine inlet.
The experimental unit is positioned on the working surface of the base module HM 150 in a simple and safe manner. The water supply and flow rate measurement are provided via HM 150. Alternatively, the experimental unit can be supplied by the laboratory supply.
The well-structured instructional material sets out the fundamentals and provides a step-by-step guide through the experiments.
Learning Objectives / Experiments
- design and function of a Pelton turbine - determination of torque, power and efficiency - graphical representation of characteristic curves for
torque, power and efficiency
* Model of a Pelton turbine resp. an impulse turbine1 * Transparent operating area1 * Adjustable nozzle cross-section1 * Loading by band brake
 function of a Pelton turbine  transparent front panel for observing the operating area  loading the turbine by use of the band brake  adjustable nozzle needle for setting different nozzle cross-sections  marking on brake drum for non-contact speed measurement  instruments: spring balances for determining the torque, manometer shows pressure at turbine inlet  flow rate determination by base module HM 150
 water supply using base module HM 150 or via laboratory supply