Measurement of Particle Velocities in an Abrasive Jet Cutting System.
Paper in Proceedings of the 6th Amer Water Jet Conf Water Jet Tech Assoc PP 291-304 :291-304
An electronic velocimeter was designed and built at the U.S. Bureau of Mines to measure quasi-instantaneous abrasive particle velocities in a three-phase abrasive jet-cutting system. The jetting system consists of a 2-mm-diam nozzle delivering 1.1 L/s (20 gpm) of water at 69 mpa (10,000 psi), directed into a 14-mm-id "collimating" pipe of variable length. The disintegrating water jet entrains abrasives and air via an entrainment port 10 cm downstream of the nozzle exit. The resulting three-phase slurry mixes in the collimating pipe. The high-velocity droplets and vapor of the disintegrating water jet transfer momentum to the slower incoming abrasives in the collimating pipe. Measurements with the electronic velocimeter were used to estimate velocity profiles for the particles and thereby determine the rate of momentum transfer. Measured data were used to construct a velocity profile for the abrasive particles. This profile was compared to theoretical profiles generated using a viscous drag model for particle acceleration.
Paper in Proceedings of the 6th Amer. Water Jet Conf., Water Jet Tech. Assoc., PP. 291-304