Master thesis and internship[BR]- Master's thesis : Experimental and Numerical Analysis of Aerodynamic Forces on Small Caliber Projectiles in Supersonic Flows[BR]- Internship

Abstract

This thesis investigates the aerodynamic properties of the 5.56 mm NATO projectile using both experimental and numerical methods. Conducted in the Royal Military Academy’s new wind tunnel, the study employs Simcenter STAR-CCM+ with the k-omega SST turbulence model for simulations validated by wind tunnel tests at Mach 2, 0° angle of attack, and a Reynolds number of 1.13e6. Key analyses include Schlieren visualization, wall static pressure measurements, and drag coefficient comparisons. The research addresses challenges such as instrument precision, setup asymmetry, and measurement uncertainties. Findings reveal a 10% discrepancy in drag coefficient between sting-mounted and confined free flight scenarios, with the confined free-flight scenario matching free-flight data. An asymmetry equivalent to an angle of attack of -0.32° was identified. The study also found that the projectile's contribution to the total drag of the setup was approximately 20%. Confidence in the wind tunnel’s flow characteristics and instruments was established, providing a foundation for future aerodynamic studies. The insights gained will guide future experimental setups and improve the accuracy of aerodynamic measurements, paving the way for more refined and accurate future research.