An Auto-Switched Chaos System Design and Experimental Study of Pulsed Cavitating Multihole Nozzle

In order to improve the rock breaking ability of jet nozzle in radial drilling technique, pulsed cavitating multihole nozzle was designed on the basis of multihole nozzle. And its modulation mechanism of pulsed cavitating jet was analyzed. Rock breaking test was carried out to compare the rock breaking results of pulsed cavitating multihole nozzle and multihole nozzle. The results indicated that the rock breaking result of pulsed cavitating multihole nozzle is better than that of multihole nozzle. The rock breaking volume is 1.23∼2.35 times. To guarantee the minimum hole diameter is bigger than nozzle diameter, jet impact pressure should not be lower than 30 MPa in the experiment. The experimental optimal standoff distance is 12 mm. The findings in this paper can increase the extension of horizontal holes and improve drilling rate in radial drilling technique.