Yao Longchao, Wu Xuecheng, Wu Yingchun, Yang Jing, Gao Xiang, Chen Linghong, Gréhan Gérard, Cen Kefa
Appl Opt. 2015 Jan 1;54(1):A23-31. doi: 10.1364/AO.54.000A23.
A digital holographic particle tracking velocimetry system is applied to quantitatively study the drop atomization induced by capillary waves, and the breakup caused by increased sound pressure levels. A wavelet-based algorithm is used for particle detection and autofocusing with a wide size range of 20 μm-2 mm. To eliminate the influence of large particles on small particles, a two-step detection method is adopted. Large drops are first characterized and simulated by a diffraction-based model. Then the contributions of the drops are subtracted from the original hologram followed by the detection of small droplets. Finally, the velocity and size distribution of the secondary droplets are obtained from the experimental holograms. The results demonstrate the validity of the digital in-line holographic technique for the atomization and breakup study of acoustically levitated drops.
一种数字全息粒子跟踪测速系统被应用于定量研究由毛细波引起的液滴雾化以及由声压级增加导致的破碎。一种基于小波的算法用于在20微米至2毫米的宽尺寸范围内进行粒子检测和自动聚焦。为了消除大粒子对小粒子的影响，采用了两步检测方法。首先通过基于衍射的模型对大液滴进行表征和模拟。然后从原始全息图中减去这些液滴的贡献，接着检测小液滴。最后，从实验全息图中获得二次液滴的速度和尺寸分布。结果证明了数字同轴全息技术在声悬浮液滴雾化和破碎研究中的有效性。
