Hong Z Y, Zhai W, Yan N, Wei B
MOE Key Laboratory of Space Applied Physics and Chemistry, Northwestern Polytechnical University, Xi'an 710072, People's Republic of China.
J Acoust Soc Am. 2014 May;135(5):2553-8. doi: 10.1121/1.4869678.
The accurate calculation of the acoustic radiation force is important for ultrasonic application techniques. Usually, the acoustic radiation force can be divided into the near-field and the far-field force according to the ratio of the emitter-reflector distance to the wavelength. In this study, appropriate theories and methods are explored to simulate the far-field and the near-field acoustic radiation force exerted on a planar reflector. The comparison between simulation and experiment indicates that the far-field force is not sensitive to the boundary shape and size while the near-field force is highly sensitive to the boundary size. Only the acoustic model with the minimized boundary size could yield the near-field force consistent with the experiment. Further calculations reveal that the far-field force first increases and then decreases with the rise of the reflector radius, and that the near-field force fluctuates with the acoustic frequency, especially when the emitter-reflector distance is very small. The near-field repulsive force can be changed into the attractive force when the acoustic frequency is lowered.
声辐射力的精确计算对于超声应用技术至关重要。通常，根据发射器与反射器的距离与波长的比值，声辐射力可分为近场力和远场力。在本研究中，探索了合适的理论和方法来模拟施加在平面反射器上的远场和近场声辐射力。模拟与实验之间的比较表明，远场力对边界形状和尺寸不敏感，而近场力对边界尺寸高度敏感。只有边界尺寸最小化的声学模型才能产生与实验一致的近场力。进一步的计算表明，远场力随反射器半径的增加先增大后减小，近场力随声频波动，特别是当发射器与反射器的距离非常小时。当声频降低时，近场排斥力可变为吸引力。
