impact of jet
IMPACT OF A JET
OBJECTIVES:
To measure the force generated by impact of the jet on vanes of various shapes.
To compare the results from the experiment with the theoretical calculations.
APPARATUS:
The Jet Impact Apparatus
Volumetric Hydraulic Bench/Water
3 different shapes of vanes; Flat Plate, Conical Cup, and Hemispherical Cup
Stop Watch
1. INTRODUCTION
One way of producing mechanical work from fluid under pressure is to use the pressure to accelerate the fluid to a high velocity in a jet. The jet is directed on to the vanes of a turbine wheel, which is rotated by the force generated on the vanes due to the momentum change or impulse which takes place as the jet strikes the vanes. Water turbines working on this impulse principle have been constructed with outputs of the order of 100,000 kW and with efficiencies greater than 90%.
In this experiment, the force generated by a jet of water as it strikes a flat plate, conical plate, and hemispherical cup may be measured and compared with the momentum flow rate in the jet.
2. DESCRIPTION OF APPARATUS
The Jet Impact Apparatus, H8, has been designed for use with the Hydraulic Bench, H1.
This provides the necessary water supply and flow measurement facility. Figure 1 shows the arrangement in which the bench supply is led to a vertical pipe terminating in a tapered nozzle. This produces a jet of water which impinges on the vane in the form of a
Flat Plate, Conical Plate, or Hemispherical Cup. The nozzle and vane are contained within a transparent cylinder; at the base of the cylinder there is an outlet by which the flow may be directed to the weighing tank.
As indicted in Fig. 1, the vane is supported by a lever which carries a jockey weight and
which is restrained by a light spring. The lever may be set to a balanced position (as indicated by the tally suspended from it) by placing the jockey weight at its zero position and then adjusting the knurled nut above the spring. Any force
OBJECTIVES:
To measure the force generated by impact of the jet on vanes of various shapes.
To compare the results from the experiment with the theoretical calculations.
APPARATUS:
The Jet Impact Apparatus
Volumetric Hydraulic Bench/Water
3 different shapes of vanes; Flat Plate, Conical Cup, and Hemispherical Cup
Stop Watch
1. INTRODUCTION
One way of producing mechanical work from fluid under pressure is to use the pressure to accelerate the fluid to a high velocity in a jet. The jet is directed on to the vanes of a turbine wheel, which is rotated by the force generated on the vanes due to the momentum change or impulse which takes place as the jet strikes the vanes. Water turbines working on this impulse principle have been constructed with outputs of the order of 100,000 kW and with efficiencies greater than 90%.
In this experiment, the force generated by a jet of water as it strikes a flat plate, conical plate, and hemispherical cup may be measured and compared with the momentum flow rate in the jet.
2. DESCRIPTION OF APPARATUS
The Jet Impact Apparatus, H8, has been designed for use with the Hydraulic Bench, H1.
This provides the necessary water supply and flow measurement facility. Figure 1 shows the arrangement in which the bench supply is led to a vertical pipe terminating in a tapered nozzle. This produces a jet of water which impinges on the vane in the form of a
Flat Plate, Conical Plate, or Hemispherical Cup. The nozzle and vane are contained within a transparent cylinder; at the base of the cylinder there is an outlet by which the flow may be directed to the weighing tank.
As indicted in Fig. 1, the vane is supported by a lever which carries a jockey weight and
which is restrained by a light spring. The lever may be set to a balanced position (as indicated by the tally suspended from it) by placing the jockey weight at its zero position and then adjusting the knurled nut above the spring. Any force