Aoki Ryota, Hattori Kanji D, Yamamoto Takuya
Department of Chemical Engineering, Graduate School of Engineering, Osaka Metropolitan University, 1-1, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
Department of Chemical Engineering, Graduate School of Engineering, Osaka Metropolitan University, 1-1, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
Ultrason Sonochem. 2025 Jun 6;120:107419. doi: 10.1016/j.ultsonch.2025.107419.
In this study, the mechanism that the sonochemical reactions are quenched due to an increase in ultrasonic power was investigated through six experiments, stability analysis, and numerical simulations. The experiments involved measuring the sonochemical reaction rate, observing sono-chemiluminescence (SCL), conducting particle image velocimetry (PIV) measurement, measuring sound pressure, observing bubble motion, and measuring the degassing rate of dissolved oxygen. Through these experiments and numerical simulations, the phenomena could be classified into three regions in response to ultrasonic power. In the region of small ultrasonic power, the superposition of ultrasound is good, and the reaction rate increases with the ultrasonic power. However, at higher ultrasonic power, the superposition of ultrasound is deteriorated, suppressing the bubble nucleation and growth due to rectified diffusion. This results in a lower fluid flow velocity due to acoustic streaming, a smaller reaction rate, and smaller degassing rate. At much higher ultrasonic power, the ultrasonic standing waves are changed into traveling waves resulting in bubble cluster formation and movement, as well as a smaller chemical reaction rate. These experimental results and the proposed mechanisms were also supported by the numerical simulation and stability analysis results.
在本研究中，通过六个实验、稳定性分析和数值模拟，研究了声化学反应因超声功率增加而淬灭的机制。实验包括测量声化学反应速率、观察声致化学发光（SCL）、进行粒子图像测速（PIV）测量、测量声压、观察气泡运动以及测量溶解氧的脱气速率。通过这些实验和数值模拟，根据超声功率，这些现象可分为三个区域。在低超声功率区域，超声叠加良好，反应速率随超声功率增加而增大。然而，在较高超声功率下，超声叠加变差，由于整流扩散抑制了气泡的成核和生长。这导致由于声流作用流体流速降低、反应速率减小以及脱气速率减小。在更高的超声功率下，超声驻波转变为行波，导致气泡簇的形成和移动，以及化学反应速率减小。这些实验结果以及所提出的机制也得到了数值模拟和稳定性分析结果的支持。
