Bryan Alfaro ’24
Mechanical and Aerospace Engineering
SuperPipe Particle Image Velocimetry Calibration
My goal was to determine a noninvasive way of calibrating a camera used in a particle image velocimetry (PIV) system, which is used to obtain instantaneous measurements of velocity and related properties in fluids. I tested a method that used the waist of a focused laser beam to create a calibration grid in the image plane. I used stepper motors to move a laser and converging-lens system around a grid, then at each position I took a long-exposure picture of the beam waist as the laser shone through the lens. Using a computer program, I found the waist’s location in each picture and mapped the set of waist points. The results showed a somewhat regular grid with occasional clusters of points that could be eliminated by averaging multiple pictures per location. This provided a proof of concept for my idea and highlighted improvements for future experiments. I learned how PIV systems are used to determine local velocities in turbulent flows, and how to write computer programs that process images and perform a camera-calibration procedure. This experience motivated me to further refine this method and determine its feasibility.
2021
Innovation and a New Energy Future
Smits Fluid Mechanics Lab, Department of Mechanical and Aerospace Engineering, Princeton University
Alexander Smits, Eugene Higgins Professor of Mechanical and Aerospace Engineering, Emeritus; Liuyang Ding, Postdoctoral Research Associate, Mechanical and Aerospace Engineering