DUAL-JET NOZZLE STRUCTURE AND ROCK CUTTING EXPERIMENT

摘要

Dual-jet, a kind of combined water jet formed by a conical jet surrounded with a swirl jet aiming at enhancing rock cutting efficiency, was designed and studied. Based on the hydrodynamics and fluid mechanics, the nozzle structure and vane surface equation of the dual-jet nozzle are presented. The rock cutting experiments were conducted and the effects of nozzle structure parameters including cone angle, outlet angle of the vanes, equivalent diameter and flux ratio between round jet and whirling jet on rock cutting efficiency are investigated: The experimental results show that the introduction of the swirl jet can augment the diameter of the cutting hole and hence improve the efficiency of rock cutting.