Experimental and Numerical Investigation of Static and Dynamic Stability of a Re-Entry Capsule in Subsonic Flow

Re-entry capsules can be approximated as blunt bodies. When flying in the low supersonic to transonic regime, these geometries tend to exhibit dynamic instability, which amplifies the oscillatory motion of the capsule. This phenomenon becomes particularly critical in missions requiring parachute deployment at low altitudes and Mach numbers. To design such vehicles effectively, a thorough understanding of their aerodynamic stability characteristics is essential. However, obtaining this information through numerical methods alone remains challenging. Experimental techniques continue to be the most reliable approach for assessing dynamic stability. Nevertheless, combining experimental data with numerical simulations offers the greatest potential. Validating computational tools against ground-based data enables a broader and more flexible aerodynamic characterization of the vehicle across different conditions and design iterations. This paper aims to contribute to this objective by providing a comprehensive aerodynamic characterization (static & dynamic) in the VKI S1 wind tunnel in the low-subsonic regime and the foundation for a validated CFD model to support future design efforts.