摘要
本文利用时域有限差分求解Westervelt方程对3600阵元平面相控阵的全电子聚焦超声场进行建模仿真,探讨声吸收系数对该相控阵全电子聚焦性能的影响。结果显示,选定焦点距离相控阵中心越远,-6 dB焦域越大,聚焦增益分布差异度越小;选定焦点偏离相控阵中心轴角度越大,-6 dB焦域越倾斜;选定焦点落在-6 dB焦域内,表明相控阵聚焦精度较好;远场-6 dB焦域聚焦增益小于近场的;相控阵未出现旁瓣,表明治疗安全性较好。声吸收系数的增大会导致最大聚焦增益大幅减小,表明了声吸收系数对最大聚焦增益有重要的影响;最大聚焦增益随声吸收系数的变化曲线比较集中,这表明发射声压幅值和非线性系数对最大聚焦增益的影响不如声吸收系数的;而且,选定焦点距离相控阵中心越远,最大聚焦增益随声吸收系数的变化曲线越集中,这说明超声传播距离越远,声吸收系数相比发射声压幅值和非线性系数对最大聚焦增益的影响越强。对于距离相控阵比较近的选定焦点,声吸收系数的增大会导致聚焦偏差有一些微弱的减小;对于距离平面相控阵比较远的选定焦点,声吸收系数的增大则会导致聚焦偏差有一定程度的增大。
This article uses time-domain finite difference to solve the Westervelt equation to model and simulate the fully-electronic focusing ultrasonic field of a 3600 element planar phased array,and explores the influence of sound absorption coefficient on the fully-electronic focusing performance of the phased array.The results show that the farther the selected focal point is from the center of the phased array,the larger the-6 dB focal field,and the smaller the difference in the distribution of focusing gain.The larger the deviation angle of the selected focus from the central axis of the phased array,the more inclined the-6 dB focal field will be.The selected focus falls within the-6 dB focal range,indicating that the phased array has good focusing accuracy.The focusing gain of the-6 dB focal field in the far field is smaller than that in the near field.The phased array showed no sidelobes,indicating good treatment safety.The increase in sound absorption coefficient leads to a significant decrease in the maximum focusing gain,indicating that the sound absorption coefficient has an important impact on the maximum focusing gain.The maximum focusing gain changing with the sound absorption coefficient is relatively concentrated,indicating that the influence of the emitted sound pressure amplitude and nonlinear coefficient on the maximum focusing gain is not as significant as that of the sound absorption coefficient.Moreover,the farther the selected focal point is from the center of the phased array,the more concentrated the changing of the maximum focusing gain with respect to the sound absorption coefficient.This indicates that the farther the ultrasonic propagation distance,the stronger the influence of the sound absorption coefficient on the maximum focusing gain compared to the amplitude of the emitted sound pressure and the nonlinear coefficient.For selected focal points that are relatively close to the phased array,an increase in sound absorption coefficient will result in a slight decrease in focusing deviation.For selected focal points that are relatively far away from the planar phased array,an increase in sound absorption coefficient will lead to a certain degree of increase in focusing deviation.
作者
王祥达
郭甲
滕世国
高翔
Wang Xiangda;Guo Jia;Teng Shiguo;Gao Xiang(Ruyuan Dongyangguang Machinery Co.,Ltd.,Shaoguan,China;Guangdong Zhongke Qingyuan Environmental Technology Co.,Ltd.,Shaoguan,China;Beijing University of Technology,Beijing,China;Intelligent Manufacturing College,Wenzhou Vocational and Technical College,Wenzhou,China)
出处
《科学技术创新》
2025年第18期215-219,共5页
Scientific and Technological Innovation
基金
国家市场监督管理总局科技计划项目(2024MK075)支持。
关键词
声吸收系数
HIFU
相控阵
电子聚焦
sound absorption coefficient
HIFU
phased array
electronic focusing
