On the calibration of astigmatism particle tracking velocimetry for microflows
On the calibration of astigmatism particle tracking velocimetry for microflows
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DOI：
10.1088/0957-0233/22/1/015401
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发表时间：
2011-01-01
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.;Rossi, M.;Kaehler, C. J.
散光粒子跟踪测速法（APTV）是一种使用单个摄像机确定体积（3D）中速度场的三个分量（3C）的方法。颗粒的深度位置由光学设置中的圆柱形透镜引起的光学畸变编码。这种技术特别适合于微流体应用，因为由于空间平均和相关深度（通常与μ PIV方法一起遇到）而产生的测量误差被消除，从而提高了测量精度。不幸的是，该技术的当前状态受到利用当前校准程序可实现的小测量区域以及更高阶图像像差的限制（Cierpka等人，2010 Meas. Sci. Technol.21045401）。为了扩大测量体积的大小，并考虑到所有的图像像差，一个新的内在的校准程序，基于粒子的成像功能，提出了在手头的文件。它提供了一个扩展的测量深度，考虑到所有的图像像差。在这项工作中，校准程序被应用到一个μ PIV安排，但也可以在宏观实验装置上实施。校准程序是合格的合成数据，以及Poiffille流在一个直的矩形微通道，横截面积为200 × 500 μ m（2）。整个通道的三维速度分布，通过APTV解决的不确定性为0.9%和3.7%的中心线速度，μ（c），平面内和平面外的组件，分别。使用不同的圆柱透镜焦距，放大倍率和颗粒尺寸的进一步研究提供了有关可实现的测量深度的信息，并有助于设计和调整所需实验的最佳系统。
Astigmatism particle tracking velocimetry (APTV) is a method to determine three components (3C) of the velocity field in a volume (3D) using a single camera. The depth position of the particles is coded by optical distortions caused by a cylindrical lens in the optical setup. This technique is particularly suited for microfluidic applications as measurement errors due to spatial averaging and depth of correlation, typically encountered with mu PIV approaches, are eliminated so that the measurement precision is enhanced. Unfortunately, the current state of the technique is limited by the small measurement region achievable with the current calibration procedures as well as by higher order image aberrations (Cierpka et al 2010 Meas. Sci. Technol. 21 045401). In order to extend the size of the measurement volume and to account for all image aberrations, a new intrinsic calibration procedure, based on the imaging function of the particles, is proposed in the paper at hand. It provides an extended measurement depth, taking into account all image aberrations. In this work, the calibration procedure was applied to a mu PIV arrangement but could also be implemented on macroscopic experimental setups. The calibration procedure is qualified with synthetic data as well as Poiseuille flow in a straight rectangular micro-channel with a cross-sectional area of 200 x 500 mu m(2). The three-dimensional velocity distribution of the whole channel was resolved via APTV with uncertainties of 0.9% and 3.7% of the centerline velocity, mu(c), for the in-plane and out-of-plane components, respectively. Further investigations using different cylindrical-lens focal lengths, magnifications and particle sizes provide information about achievable measurement depths and help to design and adapt the optimal system for the desired experiment.