Nonlinear Aerodynamic and Nonlinear Structures Interations (NANSI) Methodology for Ballute/Inflatable Aeroelasticity in Hypersonic Atmospheric Entry

ZONA proposes a phase II effort to fully develop a comprehensive methodology for aeroelastic predictions of the nonlinear aerodynamic/aerothermodynamic - structure interaction (NANSI) on ballutes during hypersonic atmospheric entry, including potential surface wrinkling. A time-accurate Boltzmann aerodynamic flow solver, called BGKX, will first be extended to 3D geometries for inviscid /viscous hypersonic flows. BGKX is a robust, unified-Mach-number, all-altitude, viscous flow solver; it provides pressure and heat flux solutions in one step. To handle the complex geometry of wrinkling ballutes, an advanced cartesian grid system, called gridless boundary condition cartesian (GBCC), will be implemented within BGKX. Next, generalized reduced order models (ROM) of the BGKX aerodynamics and nonlinear structures will be established to handle ballute wrinkling and the complex flow. In addition to Direct physical coupling of the aerodynamics and structures, an aerodynamic ROM - structures ROM coupling procedure will be fully developed for efficient aeroelastic applications to wrinkled ballutes. Lastly, we will evaluate the sensitivity of the ballute aeroelastic behavior in specific structural features: the pre-tensioning of the ballute, its inflation, and the existence of structural properties variations around its circumference. ZONA will work closely with the NASA monitor in phase II should an additional ballute configuration be considered.