基于图像测速的波浪破碎两相速度场测量方案探讨

Discussion on the improved measurement scheme of wave breaking velocity fields based on image velocimetry

中文关键词:  粒子图像测速  气泡图像测速  波浪破碎  速度场测量

英文关键词:Particle Image Velocimetry  Bubble Image Velocimetry  wave breaking  velocity field measurement

中文摘要:

      针对波浪破碎试验中气泡区速度与水体速度无法同时测量的难题，基于实验室条件，搭建了粒子图像测速 （PIV）和气泡图像测速 （BIV） 系统，采用声学多普勒测速仪 （ADV） 对 PIV 测量精度和不同场景下 BIV 测量精度进行了细致的验证，并设计多种试验方案以期实现 BIV 与 PIV 的同步耦合测量。试验结果表明，7W 激光+后置灯的优化照明方案，其耦合测量的气泡区速度代表参数与标准 BIV 照明方案的结果误差小于 5%，且耦合测量的气泡区下方水质点的速度曲线与标准PIV 测量结果吻合，表明该改进方案满足 PIV 与 BIV 耦合测量的条件。本文实现的 PIV 与 BIV 耦合测量有利于优化测量和分析工作，减小破碎波浪重复生成的影响，有利于提高测量精度，为大范围波浪破碎速度场的快速测量提供了新的方案。

英文摘要:

      In a wave breaking experiment, the velocity fields of the bubble zone and the water body are usually measured separately which caused great trouble. To solve this problem, a Particle Image Velocimetry (PIV) system and a Bubble Image Velocimetry (BIV) system are built and verified comprehensively by using Acoustic Doppler Velocimetry (ADV). Multiple experiment schemes are designed to realize simultaneous measurement of the velocity field of breaking waves. Results show that the bubble zone velocity measured by an improved scheme, with 7W laser + rear LED lights, is consistent with the result of the standard BIV lighting scheme, and the error is less than 5%. The improved scheme忆s measured velocity of the water particles below the bubble zone is consistent with the standard PIV measurement. It shows that the improved lighting scheme can achieve the simultaneous measurement of BIV and PIV, which is beneficial to the measurement and analysis work, and reduce the errors caused by repeated generation of breaking waves.