Abstract:To investigate the characteristics of abrasive jet from a conical nozzle, which is composed of a casing and a core with spiral-grooved cylinder, a series of jet impingement experiments were conducted. The parameters that can affect characteristics of jet include number of grooves, diameter of central hole in cone, working pressure, distance between nozzle outlet and target. The effects of every parameter on jet cross-section shape were investigated by single factor experiment method, a few regression equations were fitted based on the experimental data, and the reasons why those effects were shown are analyzed theoretically. The results showed that the jet cross-section shape is a solid circle or a ring. The ring ou-ter diameter becomes larger with increasing working pressure, while the inner diameter of the ring is almost the same. The impinging load of jet with single groove on the target is lower than that with two or three grooves. With increasing diameter of central hole the outer diameter of jet cross-section is decreased gradually. The cone angle of jet is almost unaffected. There is an optimum range of target distance; the outer diameter of jet cross-section gets large nearly linearly with increasing target distance; meanwhile the inner diameter is expanded as well. These experimental results can provide the basis for nozzle and spiral grooves geometrical parameters optimization and working pressure determination, and establish a theoretical and experimental basis for further improvement in jet performance.
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