Micro Particle Image Velocimetry (PIV)/Planar Laser Induced Fluorescence (PLIF)

Because of the small dimensions of the flow field in micro channel flow, it is impossible to use conventional PIV systems to obtain two orthogonal planes for optical access to the flow field. Instead, micro PIV systems use a volume illumination technique where the light source and the view field are introduced through the same optics. With this approach the focal plane is moved down through the flow field to map the entire volume. Detailed flow structures associated with channel entrance and exit effects, wall shear, impellers, etc. can be examined to assess their contribution to entropy production and in turn the degradation in performance.

An inverted Nikon Eclipse TE2000-E microscope is used to view the flow field through epi-fluorescent optics with magnification between 4X and 60X. Volume illumination of the flow field is accomplished using 15 mJ/pulse Nd:YAG laser while the images are captured using a 12-bit, 10 frames/s CCD camera. The INSIGHT software package allows for both PIV and PLIF image capture.