SEDL / STP / STP664-EB / STP35812S

Effect of an Air-Injected Shroud on the Breakup Length of a High-Velocity Waterjet

Eddingfield, DL
Assistant professor and graduate student, Southern Illinois University, Carbondale, Ill.

Albrecht, M
Assistant professor and graduate student, Southern Illinois University, Carbondale, Ill.

Pages: 12    Published: Jan 1979

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Abstract

Air-injected shrouds are used to create an airflow parallel to a high-speed waterjet to examine the effect of the air velocity on the breakup length of the waterjet. Eight shrouds having four different lengths and two different diameters are employed in this study. The air velocity was varied from zero to approximately twice the velocity of the waterjet. The waterjet has an exit diameter of 0.766 mm (0.030 in.) and an exit velocity of 266 m/s (874 ft/s) for all the experimental runs.

Of the shrouds tested, the shortest shroud with the smaller diameter produced the best results for the entire air velocity ranges. The breakup length of the waterjet with a shroud compared to that of a waterjet without a shroud ranges from 1.2 for an air-to-water velocity ratio of zero up to a value of approximately 1.7 for a velocity ratio of 2.0.

Cutting tests on a representative material are planned to establish firmly the benefit of utilizing an air-injected shroud in conjunction with a high-velocity waterjet.