Experimental Flow Visualization


This section provides details and images related to my research involving bio-inspired flight at Lehigh University.  In recent years, there has been major interest in the flow structure and loading on wings undergoing various unsteady maneuvers. The motivation for understanding biologically inspired flight at low Reynolds number comes from interest in small unmanned air vehicles. Flapping wings of insects and birds are characterized by large amplitude motions including rotation, pitching, and plunging.


In the Fluids Lab at Lehigh University we use a quantitative flow visualization technique called Particle Image Velocimetry (PIV). Particle image velocimetry (PIV) involves determining the vector velocity field of a particular flow by measuring the displacement of fine particles, in order to track the motion of the fluid.  This technique involves illumination of a plane of interest with two short bursts of laser light. The particles illuminated in each laser pulse were captured by a CCD camera system which stores each image in separate frames. The image pairs were then analyzed using software that divides each image into a grid of points, which are referred to as interrogation points. A correlation algorithm then determines the effective displacement of particles within a defined window around each interrogation point. The computer program divides the effective displacement by the time delay between laser pulses and determines a two dimensional (in-plane) velocity vector at each interrogation point. Stereoscopic particle image velocimetry (SPIV) was a technique involving a combination of two overlapping velocity vector fields, thereby resolving the out of plane velocity component. This technique provides an instantaneous three-dimensional velocity fields on a two-dimensional plane.



The following list contains links to descriptions and galleries of my most recent work.

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