High-Fidelity Simulations of a Dragonfly Lander Test Article in the National Full-Scale Aerodynamics Complex

The Dragonfly rotorcraft lander, NASA’s New Frontiers mission to Titan, will perform the critical Preparation for Powered Flight (PPF) phase following atmospheric entry and parachute descent. This phase ensures the lander transitions safely and stably from passive descent to autonomous powered flight. To better understand the complex aerodynamic environment during PPF, this study presents high-fidelity computational fluid dynamics simulations using NASA’s OVERFLOW solver. The simulations replicate wind tunnel conditions from the National Full-Scale Aerodynamics Complex and are validated against experimental data. Blade-resolved, unsteady Navier–Stokes simulations capture the rotorcraft flow physics, including rotor–lander interactions, rotor-backshell interactions, and unsteady aerodynamic loads. The results show good agreement between OVERFLOW and test data, especially in yaw moment, which is essential for the de-spin maneuver. OVERFLOW also compares well with predictions from the mid-fidelity STAR-CCM+ model, offering greater detail without requiring tuning. These findings build confidence in the aerodynamic database and support the reliability of both tools for assessing Dragonfly’s performance in Titan’s atmosphere during PPF.