STUDY ON FLOW PRINCIPLES OF ROTATING JET

Based upon the previous demonstrations of that the rotating jet produced by direction conducing jet nuzzles has a stronger capability on rock breaking and borehole making, the flow principles of rotating jet was studied. The obtained experimental results shown that the velocity and pressure distribution of rotating jet are evidently different from that of the conventional circular jet. In the area closed to the nuzzles, its velocity profile, pressure profile and profile of axial velocity represent a "M" shape distribution, and profile of tangential velocity a "N" shape distribution. As the jet prolongs further, the jet profile becomes wider and its velocity and pressure profile become flatter and they attenuate faster. Its maximum axial and tangential velocity attenuate proportionally with the negative index of its distance from the nuzzles. The experimental results also indicated that rotating jet possesses a stronger distributing capability in the direction perpendicular to its axis and a weaker axial propagating capability. The above fact provides information for rational design and use of rotating jet.