Evolution of Coupled Dynamics During Carrier–Payload Separation in High-Speed Flows

Most previous studies on carrier–payload–extraction-parachute separation systems have focused on low-speed regimes and quasi-steady aerodynamics, leaving fully coupled multibody fluid–body interactions in high-speed compressible flows and the effects of flight conditions insufficiently understood. This study investigates separation between an unpowered gliding carrier and an internal payload. A node-to-surface penalty model represents payload-adapter contact, while a dynamic fluid–body interaction model with overset meshes resolves unsteady aerodynamics and multibody motion within narrow clearances. The numerical framework is validated against a captive-trajectory wind-tunnel case at Mach 1.2, Reynolds number [Formula: see text], and an equivalent altitude of 11.6 km; subsequent simulations are conducted at 25 km over Mach 0.6–1.2. Parametric studies show that payload attitude is governed primarily by extraction-parachute drag, causing significant adapter compression near the aft end. Increasing the initial angle of attack strengthens and prolongs drag oscillations, degrading attitude stability. Increasing the freestream Mach number from subsonic to supersonic conditions raises mean drag while suppressing fluctuations. The resulting flow stabilization reduces the peak payload pitch rate and increases the minimum spacing, improving the separation margin.