This project characterized the 2D flow field around a NACA 0012 airfoil using Particle Image Velocimetry (PIV) and computational fluid dynamics (CFD). Experiments were conducted in a closed-loop water tunnel with a 4-inch chord airfoil mounted at angles of attack ranging from –14° to +14°. PIV measurements captured instantaneous velocity fields, from which boundary layer development, stagnation points, and wake structures were extracted.
Using calibrated scaling and laser timing, we generated 50 velocity snapshots per condition and computed averaged flow fields, drag coefficients, and Strouhal numbers. Results showed that increasing angle of attack produced larger velocity asymmetry, stronger vortex shedding, and higher drag coefficients. The Strouhal number increased with angle of attack, indicating higher shedding frequencies and increased wake unsteadiness.
Parallel CFD simulations were performed in ANSYS Fluent using both inviscid and viscous solvers. A water-tunnel-scale domain was meshed at multiple resolutions to evaluate mesh sensitivity. Lift, drag, and pressure distributions predicted by the CFD runs were compared to experimental data, and the trends agreed closely with the PIV-derived coefficients.
Overall, the project demonstrated the strengths and limitations of PIV and CFD, showing how both tools can be used together to analyze aerodynamic performance and flow physics around an airfoil. A compiled final report can be found here.