Modeling and Simulation of Parachute Apparent Mass Aerodynamics for the Dragonfly Mission

Analytical expressions to model the apparent mass aerodynamic forces and moments for the Dragonfly drogue and main parachutes are presented. Model parameters are based on a reconstruction of subscale parachute dynamic motions assuming steady-state coning motion in a wind tunnel. The apparent mass model formulation and model parameters are implemented in a multibody simulation. The simulation is validated against the dynamic motions measured during subscale drop tests of the Dragonfly drogue and main parachute configurations. The apparent mass aerodynamics model is applied to the end-to-end entry, descent, and landing simulation of the Dragonfly mission. The aeroshell/lander dynamics (attitude and rotation rates) simulated using the apparent mass aerodynamics (tensor model) are more conservative than the dynamics simulated using heritage apparent mass (point mass) model.