磨料浆体旋转射流的速度分布及其受聚丙烯酰胺添加剂的影响

Velocity profile of abrasive suspension swirling jet and influence of additive polyacrylamide

利用粒子成像速度场仪(PIV)对磨料浆体旋转射流的时均速度场进行了测量,得出了射流中磨料粒子的速度分布和滑移速度分布,并考察了聚丙烯酰胺添加剂对其的影响。结果表明,淹没条件下,射流中磨料粒子的速度分布仍类似于高斯分布;随喷距增加,在射流轴心附近的磨料轴向速度和滑移速度都先增加后降低;实验条件下,磨料浆体旋转射流的扩散角为20°,比非旋转射流的扩散角大1.52倍,因而旋转射流具有钻大直径孔眼的能力;聚丙烯酰胺具有抑制射流横向扩展和降低射流轴向衰减的作用,随聚丙烯酰胺质量分数的增加,射流固液两相的速度都相应提高。

Mean velocity profiles of abrasive suspension swirling jet were measured with particle image velocimetry technology under submergence condition. The bunching effect of additive polyacrylamide on the jet velocity was experimentally researched. The results show that the jet radial distribution patterns of axial abrasive velocity are similar to Gaussian distribution. The spreading angle of the jet is 20° that is 1.52 times greater than that of a corresponding non-swirling jet. The swirling jet can drill a hole of the larger diameter than the non\|swirling jet. The addition of polyacrylamide to jet fluid could inhibit the radial spreading of the jet, and thus decrease the axial attenuation rate of the jet velocity. When the polyacrylamide concentration increases, the velocity of suspended abrasive particles in the jet rises along with the surrounding fluid.