Design and Development of Test-Rig for Experimental Study of Flow Field Associated With Supersonic Retro Propulsion

Propelling future human landings on Mars involves a groundbreaking powered descent phase from supersonic conditions, a novel approach in Martian missions. The challenges arising from interactions among retrorocket engine plumes, freestream flow, and the descending vehicle present significant hurdles, impacting aerodynamic behavior during descent. While full-scale flow field simulations have been conducted computationally, existing ground and flight data lack adequacy for calibrating uncertainties in aerodynamic interference for proposed Mars descent vehicles. To address this, a wind tunnel test apparatus is designed to assess powered descent aerodynamics for large-scale human Mars entry concepts, aiming to identify gaps in computational predictive capabilities. Conducted in the South Dakota Mines’s Unsteady Supersonic Wind Tunnel, the test apparatus utilizes a sub-scale model with a 70-degree spherical cone resembling the heat shield of a low lift-to-drag vehicle. The blunt model allows exploration of nozzle plume direction, number, location, size, and area ratio effects. The study will be conducted for varying degrees of pitch, yaw, and roll. Key measurements include heatshield aerodynamic forces, discrete, and distributed pressure, and high-speed flow field visualization using Schlieren imaging. This paper comprehensively addresses the design and development of the test apparatus.