涡环空化的实验研究（英文）

发布时间：2018-01-07 08:18

本文关键词：涡环空化的实验研究（英文）　出处：《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》2017年07期 　论文类型：期刊论文

更多相关文章：空化 环状空泡 振荡周期 壁面冲击

【摘要】：目的:研究涡环空化产生的环状空泡的振荡周期及其冲击壁面溃灭的动态过程。创新点:1.通过实验方法,比较几种不同的速度环量计算模型在环状空泡振荡控制方程中的适用性。2.通过声学方法,得到环状空泡在撞击壁面溃灭过程中的频谱特征。方法:1.通过管内空泡膨胀产生高速射流;高速射流在管口处形成涡环并发生涡环空化。2.基于高速摄像进行流体分析。结论:1.在管内空泡溃灭后,环状空泡以恒定速度沿管的轴向运动,且其振荡周期几乎保持不变。2.环状空泡的振荡周期基本上满足规律:τ~R_0(ρ/ΔP)~(0.5)[ln(8/ε)]~(0.5)。3.在空泡振荡的最小直径为特征直径;根据空心涡核模型,可以计算得到最接近实验结果的速度环量值。4.当空泡冲击壁面时,空泡的环向直径将变大。5.环向直径的最大扩张比α与其截面直径与环向直径的比ε相关:α~ε~(0.25)。
[Abstract]:Aim: to study the oscillation period of annular cavitation generated by vortex ring cavitation and the dynamic process of impact wall collapse. The applicability of several different velocity loop calculation models in the governing equation of annular cavitation oscillation is compared. 2. The acoustic method is used. The spectral characteristics of annular cavitation in the process of crashing into the wall surface were obtained. Method 1. A high velocity jet was generated by cavitation expansion in the tube. Vortex ring formed at the nozzle of high speed jet and cavitation of vortex ring occurred. 2. Fluid analysis based on high speed camera. Conclusion 1. After bubble collapse, annular cavitation moves along the axial direction of the tube at constant velocity. The oscillatory period of annular cavitation basically satisfies the rule: 蟿 ~ + R _ (0) (蟻 / 螖 P ~ (+) ~ (0. 5)). [The minimum diameter of cavitation oscillation is characteristic diameter. According to the hollow vortex core model, the value of velocity loop, which is the closest to the experimental results, can be calculated. 4. The circumferential diameter of the cavitation will become larger. 5. The maximum expansion ratio (伪) of the annular diameter is correlated with the ratio 蔚 of the section diameter to the ring diameter: 伪 ~ 蔚 = 0.25%.
【作者单位】： State
【基金】：supported by the National Natural Science Foundation of China(Nos.51475415 and 51405429) the Zhejiang Provincial Natural Science Foundation for Distinguished Young Scholars(No.LR15E050001) the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(No.51521064)
【分类号】：O35
【正文快照】： 1 IntroductionVortex-ring cavitation,induced by a submergedjet,is a less common phenomenon that makes the jetmore erosive than a single-phase liquid jet.Thepressure oscillations of cavitation bubbles can en-hance erosion effects due to the frequently var

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