proceedings of the fourth us water jet conference - Waterjet ...

appear considerably different than the sample jet shown in Figure 1. In this way, a variety
of pulses can be included in one jet. For example, one pulse may create "water hammer"
on the target surface, another may clear out residual water and material with a "shaped
change" leading edge and another protect the entire stream from aerodynamic disruption.
Time-Independent Combinations
Experimental evidence shows the benefits of being able to "dial-in" jet
performance features to create maximum target damage. The parameters can be searched
by the operator at will, independent of any time frame. The range of Percussive Jet
variables can be much greater than in the time-dependent combinations. This approach to
jet cutting is especially beneficial when working with inhomogeneous materials.
SUMMARY
1. Being able to control frequency, amplitude and waveform in pulsed jets is not only
important but essential if the full potential of pulsed jets is to be realized.
2, A variety of different pulses can be incorporated in a single jet in a time dependent or
time-independent manner.
REFERENCES
1. Nebeker, E.B. and Rodriguez, S.E., "Percussive Water Jets for Rock Cutting," Proc.
Third International Symposium on Jet Cutting Technology, BHRA Fluid Engineering,
1976, Paper BI, 9 pp.
2. Nebeker, E.B. and Rodriguez, S.E., "Percussive Water Jets for Rapid Excavation,"
1973, Scientific Associates, Inc.
3. Nebeker, E.B. and Rodriguez, S.E., "Development of Percussive Water Jets," 1979,
Scientific Associates, Inc.
4. Nebeker, E.B. and Rodriguez, S.E., "Pulsing Water Jets," Proc. Seventh International
Symposium on Jet Cutting Technology, BHRA Fluid Engineering, 1984.
5. Donnelly, R.J. and Glaberson, W., "Experiments on the Capillary Instability of a
Liquid Jet," Proc. Roy. Soc. London, 1966, A290.
6. Houlston, R. and Vickers, G W., "Surface Cleaning Using Water-Jet Cavitation and
Droplet Erosion," Proc. Fourth International Symposium on Jet Cutting Technology,
BHRA Fluid Engineering,~ 1978, Paper H1, 18 pp.
7. Nebeker, E.B., "Standoff Distance Improvement Using Percussive Jets," Proc Second
U.S Water Jet Conference, 1983, 10 pp
8. F. Nebeker, E.B., "Development and Test of LargeDiameter Percussive Jets," 1982,
Scientific Associates, Inc.
9. Leach, S.J. and Walker, G.L., "Some Aspects of Rock Cutting by High Speed Water
Jets," Phil. Trans. Roy. Soc. London, 1966,
10. Brunton, J.H., "Deformation of Solids by Impact of Liquids at High Speeds," Erosion
and Cavitation, Amer. Soc. Testing Mats., ASTM STP 307, 1962.
11. Cooley, l'[.C., "Rock Breakage by Pulsed High Pressure Water Jets," Proc. First
International Symposium on Jet Cutting Technology, BHRA Fluid Engineering, 1972,
Paper B7.
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