复合材料边界厚度对单空泡溃灭的影响及机理  

Influence of Composite Boundary’s Thickness on Collapse Mechanism of Single Cavitation Bubble

作　　者：周瑞泉 张敏弟[1] 郑汉文 韩磊 黄彪[1] ZHOU Ruiquan;ZHANG Mindi;ZHENG Hanwen;HAN Lei;HUANG Biao(School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081)

机构地区：[1]北京理工大学机械与车辆学院,北京100081

出　　处：《机械工程学报》2025年第6期285-298,共14页Journal of Mechanical Engineering

基　　金：国家自然科学基金资助项目(51979003)。

摘　　要：由于复合材料诸多优点对于高性能水力设备的研发至关重要,此论文结合高速纹影观测技术与图像处理技术观测分析三种厚度复合材料边界附近单个空泡的溃灭过程纹影图像,讨论单空泡溃灭冲击波及周围流场结构的演化过程。进而,采用水听器压力信号测量系统监测单空泡流场压力波动过程,并提取频谱特性。研究表明,复合材料边界厚度对空泡溃灭演化过程、冲击波压力及其时频特性有显著影响。当γ=1.0时,三种厚度复合材料边界附近空泡溃灭过程及压力存在明显差异,当空泡溃灭时主要经历了膨胀、收缩、回弹三个阶段。空泡膨胀时,不同厚度边界附近空泡横纵泡径比d^(*)随无量纲距离γ值变化趋势不同;空泡收缩时,空泡在厚度δ=0.5 mm边界附近发生分裂溃灭,在δ=1.0 mm与2.0 mm边界产生高速射流;空泡回弹时,空泡在δ=0.5 mm边界附近溃灭产生双环冲击波,在δ=1.0 mm与2.0 mm边界附近溃灭只产生单环冲击波。同时,δ=0.5 mm边界附近空泡溃灭可检测到三次压力峰值,δ=1.0 mm与2.0 mm边界附近仅检测到两次压力峰值。随着γ的增加,压力信号内不同频率成分的对应强度逐渐增加,边界厚度越小对空泡溃灭压力影响越小。The many advantages of composite materials are crucial for the development of high-performance hydraulic machinery.In the paper,the schlieren image of the collapse process of a single cavitation near the composite boundaries of three thicknesses is observed and analyzed by combining high-speed schlieren observation technology and image processing technology.The evolution process of the shock wave of single cavitation collapse and the surrounding flow field structure is also discussed.Furthermore,the paper utilizes a hydrophone pressure signal measurement system to monitor the pressure fluctuation process in the bubble flow field and extracts spectral characteristics.The study shows that the thickness of the composite material boundary significantly affects the evolution process of the bubble collapse,the pressure of the shock wave,and its frequency-time characteristics.Whenγ=1.0,the study found that there are significant differences in the bubble collapse process and pressure at the boundaries of the three types of composite materials.The main stages include expansion,contraction,and rebound when the bubble collapses.During bubble expanding,the cross-sectional diameter ratio d^(*)of the bubbles varies differently as a function of the dimensionless distanceγfrom the different thickness boundaries.During the contraction phase,the bubble divided-collapses at theδ=0.5 mm boundary and generates high-speed jets at theδ=1.0 mm and 2.0 mm boundaries.During the rebound phase,the bubble collapses to produce a double-ring shockwave near theδ=0.5 mm boundary,while only a single-ring shockwave occurs near theδ=1.0 mm and 2.0 mm boundaries.At theδ=0.5 mm boundary,three pressure peaks can be detected during collapse,whereas only two pressure peaks are observed at theδ=1.0 mm and 2.0 mm boundaries.Asγincreases,the intensity of the frequency components in the pressure signal gradually increases,and the influence on the bubble collapse decreases with decreasing boundary thickness.

关 键 词：空泡溃灭 复合材料 冲击波 压力信号 连续小波变换 

分 类 号：O352[理学—流体力学]