Analysis of Rock Breaking Parameters and Simulation of Mechanical Characteristics of Multi-Nozzle Jet Impact

With the continuous development of high-pressure water jet technology, research on optimization structural parameters for multi-nozzle configurations, perforation effect rotational impact rock breaking, and force during breaking has received increasing attention. Through a self-designed drilling test device, experiments were conducted sandstone different strengths using streams with inclination angles, various combinations nozzles, target distances, speeds. The structure drill bit optimized, jet-rock effects was studied. rationality inclination-angle in verified ALE-FEM coupling method. changes body fragmentation mode analyzed. results showed that under condition adjustable smaller angle resulted greater depth diameter while larger width breaking. optimal combination determined to be 20°, 30°, 60°, which achieved balance between borehole expansion performance. efficiency decreased distance, range being 2 4 mm. speed stream had significant rock-breaking efficiency. Under same distance conditions, as increased, volume initially increased then decreased, rate attenuation distance. forms not identical. Jet angles mainly caused tensile failure through axial impact, those primarily shear radial impact. This study provides valuable guidance optimizing bits researching