Aeroelastic Design Considerations of a Clamped Ballute for Titan Aerocapture

Abstract

The Ballute Aeroelastic Analysis Tool, an in-house tool that loosely couples aerodynamics with structural dynamics, is used to compute static deformed shapes and stresses of a clamped ballute along a Titan Aerocapture trajectory, and to determine if a clamped ballute flutters at the peak dynamic pressure point. Static solutions along a Titan aerocapture trajectory indicate that stress and displacement are correlated to dynamic pressure above 1 Pa. For lower dynamic pressures, the aerodynamic loading is insufficient to fully overcome initial material shape, indicating that spacecraft re-contact is possible, and leading to a recommendation to include supports for the torus. Dynamic analysis of the clamped ballute using a first-order engineering estimate of unsteady aerodynamics indicates that flutter will not be a problem at the peak dynamic pressure point on the trajectory. V ∞ Free-stream velocity vector. y Linear velocity, m/s.