This lab used Particle Image Velocimetry (PIV) to study flow patterns around two geometries: a cylinder and a cow silhouette, chosen for its complexity and popularity in fluid dynamics studies (and memes).

We fabricated both geometries using laser-cut 5.7mm material, with the cylinder modeled in SolidWorks and the cow geometry scaled to 40mm. We then put the Laser cut geometries into a bath of salt water with green tracer particles. A Lorenz force was applied on the bath to induce relatively even motion.

This motion could be captured and fed into our PIV program which recognizes the movements of these tracer particles frame-by-frame and can translate this into velocity vectors.

PIV experiments revealed expected flow behaviors for the cylinder, including steady separation bubbles at low speeds (Re = 55.3) and oscillating Karman vortex streets at higher speeds (Re = 849.9). The cow geometry showed smoother flow over the head and back, with flow separation and vortices around the legs.

COMSOL simulations supported these findings, with 2D simulations providing a closer match to experimental results due to reduced wall effects, while 3D simulations revealed additional nuances like backflow and boundary layer development.

This project taught me how to combine experimental PIV results with computational modeling in MATLAB to analyze fluid flows. I focused on running and interpreting COMSOL simulations, learning how different boundary conditions and flow depths affect results.

These experiences have solidified my skills in fluid dynamics and computational modeling. It was a good opportunity to see the advantages of both experimental and numerical modeling.