CFD Analysis of Atmospheric Boundary Layer Measurements on Planetary Rotorcraft
Keywords
Atmospheric Boundary Layer, Computational Fluid Dynamics, Meteorological Measurements, Wind Measurement, Rotorcraft, Dragonfly, Titan
Presenter Abstract
The Dragonfly mission will deploy a rotorcraft lander equipped with the Dragonfly Geophysics and Meteorology Package (DraGMet) to explore Titan’s surface and atmosphere through measurements of wind velocity, pressure, temperature, and atmospheric conditions. However, the vehicle’s bluff body geometry presents a challenge common amongst UAS atmospheric measurements, as flow disturbances around the lander create directionally dependent sensor biases. This study employs high-fidelity computational fluid dynamics (CFD) simulations to characterize measurement errors in DraGMet’s meteorological sensor suite. Simulations were conducted across multiple azimuthal wind angles, extracting velocity data at fixed sensor locations and computing wall shear stress distributions across the vehicle surface. Results reveal substantial directional dependence in sensor performance, with certain sensors providing significantly degraded readings depending on wind direction relative to vehicle orientation. By systematically mapping sensor reliability across wind angles, this analysis identifies which sensors deliver accurate measurements under specific flow conditions and which should be excluded to maintain data quality. This characterization is critical for interpreting Dragonfly’s atmospheric observations on Titan, where accurate wind measurements are essential for understanding ambient wind-driven sediment transport and dune formation within the moon’s 3-kilometer-thick planetary boundary layer. The methodology demonstrates broad applicability to terrestrial UAS operations, where understanding vehicle flow disturbances is essential for mission planning and atmospheric data quality assessment.
Presentations
Presented in Session 2: Platform Development II
CFD Analysis of Atmospheric Boundary Layer Measurements on Planetary Rotorcraft
The Dragonfly mission will deploy a rotorcraft lander equipped with the Dragonfly Geophysics and Meteorology Package (DraGMet) to explore Titan’s surface and atmosphere through measurements of wind velocity, pressure, temperature, and atmospheric conditions. However, the vehicle’s bluff body geometry presents a challenge common amongst UAS atmospheric measurements, as flow disturbances around the lander create directionally dependent sensor biases. This study employs high-fidelity computational fluid dynamics (CFD) simulations to characterize measurement errors in DraGMet’s meteorological sensor suite. Simulations were conducted across multiple azimuthal wind angles, extracting velocity data at fixed sensor locations and computing wall shear stress distributions across the vehicle surface. Results reveal substantial directional dependence in sensor performance, with certain sensors providing significantly degraded readings depending on wind direction relative to vehicle orientation. By systematically mapping sensor reliability across wind angles, this analysis identifies which sensors deliver accurate measurements under specific flow conditions and which should be excluded to maintain data quality. This characterization is critical for interpreting Dragonfly’s atmospheric observations on Titan, where accurate wind measurements are essential for understanding ambient wind-driven sediment transport and dune formation within the moon’s 3-kilometer-thick planetary boundary layer. The methodology demonstrates broad applicability to terrestrial UAS operations, where understanding vehicle flow disturbances is essential for mission planning and atmospheric data quality assessment.