对于多相流体介质在准直管内有阻流动过程进行了数值分析 ,讨论了准直管结构参数对磨粒加速效果的影响。理论与试验研究表明 ,磨粒在准直管入口段加速度很大 ,经过 0 .5m的加速距离后基本上达到了最大速度。准直管应用管长范围为 0 .4～ 1.5m 管径越小磨粒加速越快 ,长准直管适宜采用较大的管径 ,短管应采用小直径。采用管径较大的准直管时射流的冲蚀性能较好 ,采用管径较细的准直管时射流的切割性能较好。 The numerical analysis of the impeding flow of multiphase fluid medium in the collimator was carried out. The influence of the collimator structural parameters on the acceleration of the abrasive particles was discussed. Theoretical and experimental studies show that the abrasive particles have a great acceleration at the inlet of the collimator and basically reach the maximum velocity after accelerating distance of 0.5m. Collimator tube length range of application is 0.4 ~ 1.5m The smaller the diameter of the abrasive acceleration, the longer the collimator suitable for larger diameter, short tube should be small diameter. The jetting performance of the collimation tube with larger diameter is better, and the jet cutting performance is better when the collimation tube with smaller diameter is used.