This study explores the mitigation of cavitation damage in hydraulic engineering through air entrainment. The primary aim is to experimentally analyze the shock wave characteristics emitted by cavitation bubbles adjacent to air bubbles affixed to a tube nozzle. The schlieren optical system is utilized to visualize the shock wave, while a hydrophone measures its pressure. Experiments are conducted on cavitation bubbles induced by the spark-generated method in the vicinity of air bubbles, varying the dimensionless distances and sizes of the air bubbles. The results indicate that (1) The introduction of an air bubble noticeably changes the morphology, kinematic behavior, and shock wave features of the cavitation bubble. (2) Four distinct shock wave patterns are identified based on the quantity and shape of the shock wave, with variations in the cavitation bubble's collapsing behavior and shock wave characteristics across different patterns. (3) The dimensionless distance γ and size δ exert significant influence on the shock wave's quantity, pressure peak, shape, and energy. With decreases or increases, the shock wave quantity increases while the shock wave intensity decreases. This investigation of the interaction between cavitation bubbles and air bubbles is essential for elucidating the mechanism through which air entrainment mitigates cavitation damage.

中文翻译：

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气泡附近空化泡发射激波特性的实验研究

本研究探讨了通过夹气来减轻水利工程中的气蚀损害。主要目的是通过实验分析与固定在管喷嘴上的气泡相邻的空化气泡发出的冲击波特性。纹影光学系统用于可视化冲击波，而水听器则测量其压力。对气泡附近由火花产生方法引起的空化气泡进行了实验，改变了气泡的无量纲距离和尺寸。结果表明：（1）气泡的引入显着改变了空化泡的形态、运动学行为和冲击波特征。 (2)根据冲击波的数量和形状，识别出四种不同的冲击波模式，不同模式下空化泡的破裂行为和冲击波特征存在差异。 (3) 无量纲距离γ和尺寸δ对冲击波的数量、压力峰值、形状和能量有显着影响。随着减少或增加，冲击波数量增加，而冲击波强度减小。对空化气泡和气泡之间相互作用的研究对于阐明空气夹带减轻空化损害的机制至关重要。