Free-Surface Shear Layer Instabilities on a High-Speed Liquid Jet
Free-Surface Shear Layer Instabilities on a High-Speed Liquid Jet
复制标题
高速液体射流的自由表面剪切层不稳定性
DOI：
10.13182/fst00-a124
复制
发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Y. Kukita
中科院分区：
文献类型：
--
作者：
K. Itoh;Y. Tsuji;H. Nakamura;Y. Kukita
摘要 研究了高速液体射流自由表面下剪切层的不稳定性。这种不稳定性会在液态金属射流目标上产生波浪，对目标性能产生不利影响。最不稳定的波数和扰动的空间增长率是用线性稳定性理论预测的，并且与水射流的实验数据非常吻合。分析了流体表面张力和流线曲率对不稳定性的影响，以评估水数据对液态金属弯曲射流的适用性。结果表明，当基于剪切层厚度的韦伯数大于6时，表面张力效应可以忽略不计；当曲率半径大于剪切层厚度30倍以上时，流线曲率效应可以忽略不计。
Abstract The instabilities of the shear layer beneath the free surface of high-speed liquid jets are investigated. Such instabilities will generate waves on liquid-metal jet targets, affecting adversely the target performance. The most unstable wave number and the spatial growth rate of perturbation are predicted with linear stability theories and are shown to agree fairly well with experimental data for water jets. The effects of fluid surface tension and streamline curvature on the instabilities are analyzed to evaluate the applicability of water data to liquid-metal curved jets. It is shown that the surface tension effects are negligible when the Weber number based on the shear layer thickness is greater than six, and also the streamline curvature effects are negligible when the radius of curvature is more than 30 times greater than the shear layer thickness.