Subscale Test Program for the Orion Conical Ribbon Drogue Parachute

Abstract

A subscale wind tunnel test program for Orion's conical ribbon drogue parachute is under development. The desired goals of the program are to quantify aerodynamic performance of the parachute in the wake of the entry vehicle, including understanding of the coupling of the parachute and command module dynamics, and an improved understanding of the load distribution within the textile elements of the parachute. The test program is conducted in a 3x2.1 m (10x7 ft) closed loop subsonic wind tunnel. The subscale test program is uniquely suited to probing the aerodynamic and structural environment in both a quantitative and qualitative manner. Non-intrusive diagnostics, including Particle Image Velocimetry for wake velocity surveys, high speed pressure transducers for canopy pressure distribution, and a high speed photogrammetric reconstruction, will be used to quantify the parachute's performance. NomenclatureD o = Parachute nominal diameter d = Command module maximum diameter x/d = Non-dimensional trailing distance C D = Drag coefficient q = Dynamic Pressure Re = Reynolds number α = Angle of attack T inf = Free stream temperature ρ = Density µ = Viscosity T inf = Free stream temperature S o = Parachute nominal area

Testing Small CPAS Parachutes Using HIVAS

“…Only a limited set of four clean-wake Drogue data points were available with the smaller L s /D o ratio: DDT-1, DDT-2, DDT-3, and a 10% scale Texas A&M University Wind Tunnel Test. 11 All of these tests were considered to be in a "clean" wake. The resulting distribution published in CPAS Model Memo v11 did not have a central tendency, so a uniform dispersion was used.…”