淹没条件下水射流喷嘴内外流场特性

基于水射流技术环保、取材方便和切割能力强的特点,提出一种应用水射流切割礁石的方法。通过建立二维平面数学模型,对淹没条件下高压水射流运动特性进行模拟计算。结果表明,射流初始段为冲击速度最大、动压最大且能量最为集中的区域。淹没水深0～30 m内,伴随着水深围压的增加,初始段速度衰减不足5 m/s,衰减程度仅约1. 5%。在水流流速0～5 m/s的淹没环境中,射流初始段受水流冲击作用影响较小,水平方向速度分量变化仅在8. 5 m/s内,射流未发生明显偏离,仍具备较好的冲击流态。

Characteristics of flow field inside and outside nozzle of water jet under submerged condition

Based on the characteristics of water jet technology,such as environmental protection,easy access to materials and strong cutting ability,we propose a method of using water jet to cut reefs.By establishing a two-dimensional plane mathematical model,we simulate and calculate the motion characteristics of high-pressure water jet under submerged condition.The results show that the initial section of the jet is the region where the jet impingement velocity is the largest,the dynamic pressure is the largest and the energy is the most concentrated.The submerged water depth is from 0 m to 30 m,with the increase of water depth confining pressure,the initial stage velocity attenuation is less than 5 m/s,and the attenuation degree is only about 1.5%.In the submerged environment of 0 m/s to 5 m/s,the impact of water flow on the initial stage of the jet is relatively small.The variation of horizontal velocity component in the initial stage of the jet is only within 8.5 m/s,and there is no obvious deviation,so it still has a good impacting flow pattern.