A simple single camera 3C3D velocity measurement technique without errors due to depth of correlation and spatial averaging for microfluidics
A simple single camera 3C3D velocity measurement technique without errors due to depth of correlation and spatial averaging for microfluidics
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DOI：
10.1088/0957-0233/21/4/045401
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发表时间：
2010-04-01
影响因子：
2.4
通讯作者：
Kaehler, C. J.
中科院分区：
文献类型：
--
作者：
Cierpka, C.;Segura, R.;Kaehler, C. J.
提出了一种利用单摄像机确定微体积（3D）中速度场三分量（3C）的方法。该技术是基于跟踪单个粒子的运动，以排除由于相关深度（DOC）和空间平均的误差，如在μ PIV（微粒子图像测速）。颗粒的深度位置通过光学设置中的圆柱形透镜引发的光学畸变来编码。为了估计颗粒的位置，基于连续小波分析和自相关的处理算法。该算法工作稳健，并给出了准确的结果相比，多摄像机系统（层析PIV，V3V）。应用粒子跟踪来确定体积中的全3C速度矢量，而没有由于空间平均和DOC而产生的误差，这是由于询问窗口大小和体积照明而导致的mu PIV的固有限制。为了证明适用性，在横截面为500 × 500 μ m（2）的直通道中进行了测量。在观察方向上的测量体积的深度被选择为90 μ m，以解决近壁梯度。采用波前变形粒子跟踪测速技术可以清晰地得到整个流道的三维速度分布。
A method to determine the three components (3C) of the velocity field in a micro volume (3D) using a single camera is proposed. The technique is based on tracking the motion of individual particles to exclude errors due to depth of correlation (DOC) and spatial averaging as in mu PIV (micro particle image velocimetry). The depth position of the particles is coded by optical distortions initiated by a cylindrical lens in the optical setup. To estimate the particle positions, a processing algorithm was developed based on continuous wavelet analysis and autocorrelation. This algorithm works robustly and gives accurate results comparable to multi-camera systems (tomographic PIV, V3V). Particle tracking was applied to determine the full 3C velocity vector in the volume without the error due to spatial averaging and DOC, which are inherent limitations in mu PIV due to the interrogation windows size and volume illumination. To prove the applicability, measurements were performed in a straight channel with a cross section of 500 x 500 mu m(2). The depth of the measurement volume in the viewing direction was chosen to be 90 mu m in order to resolve the near-wall gradients. The three-dimensional velocity distribution of the whole channel could be resolved clearly by using wave front deformation particle tracking velocimetry.