A simple single camera 3C3D velocity measurement technique without errors due to depth of correlation and spatial averaging for microfluidics

作者：Cierpka C^*; Segura R; Hain R; Kaehler C J

来源：Measurement Science and Technology, 2010, 21(4): 045401.

DOI：10.1088/0957-0233/21/4/045401

• microfluidics
• 3D3C particle tracking velocimetry
• depth of correlation
• astigmatism

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.

• 出版日期2010-4