Wall Shear Stress Measurements Using A MTV-Based Plenoptic Microscope
P. D. Huck, C. Fort, P. M. Bardet
Department of Mechanical and Aerospace Engineering, The George Washington University, USA
In this contribution, we describe the first ever microscopic Molecular Tagging Velocimetry (MTV) measurements using Integral Imaging. This technique permits the measurement of the 3D-2C velocity field in an axi-symmetric stagnation jet and observed profiles agree well with analytical predictions. Standard reconstruction algorithms are compared against more advanced deconvolution algorithms and impressive improvements in reconstructed probe resolution are obtained. Integral imaging is compared with a scanning confocal microscope which serves as a basis of comparison and good agreement is achieved. The flow facility was designed for a low Reynolds number, but with an adjustable viscous length scale comparable with higher Reynolds number flows. Our instrument proves capable of resolving viscous length scales on the order of 30 micrometers which can be improved by increasing the numerical aperture of the microscope objective.