This paper examines the effect of multi-nozzle bit on sandstone specimens by means of numerical simulation and experiment, and the rationality is verified. Numerically, the effects of jets with different diameters and angles on rock were simulated by using LS-DYNA, and the rock-breaking shapes of jets with different angles are analyzed. Experimentally, the effects of jet pressure, impact standoff distance, erosion time and rotation speed on the crushing effect of sandstone are studied by building an experimental platform of high-pressure water jet impacting sandstone. The research shows that the rock-breaking depth decreases with the increase of the inclination angle, and the rock-breaking width increases with the increase of the inclination angle. Through comparing the rock-breaking depth and width, the reasonable structure of nozzle with diameter of 1.0 mm and inclination angle of 20°, 30° and 60° are determined. The volume of broken rock gradually increases with the increase of jet pressure, and the numerical simulation results are consistent with the experimental results. Meanwhile, the rock-breaking efficiency gradually decreases with the increase of the standoff distance, and gradually increases with the increase of the erosion time, and finally stabilizes. Through experiments, it is found that the rock-breaking depth, width and volume decrease with the increase of the rotation speed. The optimal standoff distance for the rock-breaking efficiency is 3 mm, the erosion time is no less than 60 s, and the critical rotation speed is 300 rpm.

本文通过数值模拟和实验研究了多喷嘴钻头对砂岩标本的影响，并验证了其合理性。在数值上，使用LS-DYNA模拟了不同直径和角度的射流对岩石的影响，并分析了不同角度的射流的破岩形状。通过建立高压水射流冲击砂岩实验平台，研究了射流压力，冲击距离，冲蚀时间和转速对砂岩破碎效果的影响。研究表明，破岩深度随倾斜角的增大而减小，而破岩宽度随倾斜角的增大而增大。通过比较破岩的深度和宽度，确定直径为1.0 mm且倾斜角度为20°，30°和60°的喷嘴的合理结构。随着射流压力的增加，破碎岩石的体积逐渐增加，数值模拟结果与实验结果吻合。同时，破岩效率随着距离的增加而逐渐减小，随着侵蚀时间的增加而逐渐增加，最终达到稳定。通过实验发现，随着转速的增加，破岩深度，宽度和体积减小。破岩效率的最佳支座距离为3 mm，腐蚀时间不少于60 s，临界转速为300 rpm。随着射流压力的增加，破碎岩石的体积逐渐增加，数值模拟结果与实验结果吻合。同时，破岩效率随着距离的增加而逐渐减小，随着侵蚀时间的增加而逐渐增加，最终达到稳定。通过实验发现，随着转速的增加，破岩深度，宽度和体积减小。破岩效率的最佳支座距离为3 mm，腐蚀时间不少于60 s，临界转速为300 rpm。随着射流压力的增加，破碎岩石的体积逐渐增加，数值模拟结果与实验结果吻合。同时，破岩效率随着距离的增加而逐渐减小，随着侵蚀时间的增加而逐渐增加，最终达到稳定。通过实验发现，随着转速的增加，破岩深度，宽度和体积减小。破岩效率的最佳支座距离为3 mm，腐蚀时间不少于60 s，临界转速为300 rpm。破岩效率随着距离的增加而逐渐减小，随着侵蚀时间的增加而逐渐增加，最终达到稳定。通过实验发现，随着转速的增加，破岩深度，宽度和体积减小。破岩效率的最佳支座距离为3 mm，腐蚀时间不少于60 s，临界转速为300 rpm。破岩效率随着距离的增加而逐渐减小，随着侵蚀时间的增加而逐渐增加，最终达到稳定。通过实验发现，随着转速的增加，破岩深度，宽度和体积减小。破岩效率的最佳支座距离为3 mm，腐蚀时间不少于60 s，临界转速为300 rpm。