Background-oriented Schlieren technique with vector tomography for measurement of axisymmetric pressure fields of laser-induced underwater shock waves
Background-oriented Schlieren technique with vector tomography for measurement of axisymmetric pressure fields of laser-induced underwater shock waves
复制标题
用于测量激光诱导水下冲击波轴对称压力场的矢量层析成像背景导向纹影技术
DOI：
10.1007/s00348-022-03524-4
复制
发表时间：
2022
影响因子：
2.4
通讯作者：
Y.,
中科院分区：
文献类型：
--
作者：
Ichihara;S.;Shimazaki;T.;Tagawa;Y.,
针对现有基于CT的背景纹影技术在测量激光水下冲击波压力场时存在的问题，提出了一种基于CT的背景纹影技术。为此，提出了一种新的基于矢量层析成像（VT-BOS）的轴对称目标BOS技术。该技术的显著特点是重建具有非零发散的轴对称矢量场，如激光诱导水下冲击波场。该方法基于轴对称矢量场的投影与重构矢量场之间的近似关系。为了比较，用VT-BOS、CT-BOS和针式水听器测量了水下冲击波的压力场。它被发现，VT-BOS是显着优于CT-BOS更好的收敛，更少的依赖于所获取的图像的空间分辨率，和更低的计算成本。该方法不仅适用于流体力学领域，也适用于其他领域的轴对称目标，如电磁学和热力学。图形摘要
This study aims to overcome the problems that existing background-oriented schlieren (BOS) techniques based on computed tomography (CT-BOS) face when measuring pressure fields of laser-induced underwater shock waves. To do this, it proposes a novel BOS technique based on vector tomography (VT-BOS) of an axisymmetric target. The remarkable feature of the proposed technique is the reconstruction of an axisymmetric vector field with nonzero divergence, such as the field of a laser-induced underwater shock wave. This approach is based on an approximate relation between the projection of the axisymmetric vector field and the reconstructed vector field. For comparison, the pressure fields of underwater shock waves are measured with VT-BOS, CT-BOS, and a needle hydrophone. It is found that VT-BOS is significantly better than CT-BOS in terms of better convergence, less dependence on the spatial resolution of the acquired images, and lower computational cost. The proposed technique can be applied not only to fluid dynamical fields, but also to other axisymmetric targets in other areas, such as electromagnetics and thermodynamics.Graphical abstract