中文摘要：

为提高高压水射流煤层割缝器的切割能力，提出采用双梯度结构对喷嘴这一关键部件进行结构设计及优化来改善喷嘴喷射性能的新思路。针对安装于Ф63割缝器总长为17mm的双梯度喷嘴，在正交实验指导下，采用Realizable k-ε湍流模型对不同参数组合下喷嘴出口流场进行了模拟。数值模拟结果表明双梯度喷嘴结构参数为L1=6mm、θ1=18°、θ2=35°、L=6mm、d=2．5mm时，其轴向速度在150mm靶距处最大且衰减较慢。通过对数值模拟优化喷嘴结构进行试制，在室内运用3DPIV对其性能实验测试。实验结果表明在本文实验条件下，双梯度喷嘴结构参数为L1=6mm、θ1=18°、θ2=35°、L=6mm、d=2．5mm时，其射流出口流场平均速度最大，速度场分布较为理想，在150mm靶距处的平均速度为普通喷嘴的1．4倍。

英文摘要：

To enhance the ability of slotted device used in coal mines, a method of re-designing and optimizing the structure of slotted device is proposed. The objective of the research is dual gradient nozzle which is installed on a Ф63 slotted device. Based on orthogonal experiments, the realizable k-ε turbulence model is established to simulate the output flow distribution of the dual gradient nozzle with different parameters. The results show that when the L1=6mm、θ1=18°、θ2=35°、L=6mm and d=2.5mm, the axial velocity reaches its peak at 150 mm from the target and then drops slowly. Based on the simulations, experiments of ability of nozzles are made on 3DPIV in the laboratory. The results show that when the parameters are L1=6mm、θ1=18°、θ2=35°、L=6mm and d=2.5mm, the average velocity of the output flow distribution has its maximum value and the velocity distribution is reasonable. The average velocity of the dual gradient nozzle at 150 mm from the target is 1.4 times of that of ordinary nozzles.