Dust Entrainment by Rotor Downwash in Variable Pressure Environments
R.M. van der Voort (TU Delft - Aerospace Engineering)
S.J. de Vet – Mentor (TU Delft - Aerospace Engineering)
L.L.A. Vermeersen – Graduation committee member (TU Delft - Civil Engineering & Geosciences)
E.J.O. Schrama – Graduation committee member (TU Delft - Aerospace Engineering)
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Abstract
Rotor downwash that lifts dust from the ground, often called brownout on Earth, has long challenged safe rotorcraft operations. As flight moves from dense terrestrial air toward thin, planetary atmospheres, the physics change: the same rotor, at the same height, produces a very different near-surface flow. If the minimum conditions needed to mobilize dust grains and the effects of the dust once in motion are misjudged, landings, takeoffs, and low-altitude manoeuvrers can become unsafe, sensors can be degraded, and contamination risks can rise. Despite extensive understanding of brownout at Earth sea level, the physics of rotor-induced entrainment under reduced pressure remains poorly constrained.
This thesis addresses that gap by posing a focused objective: contribute to safer and more predictable rotorcraft operations in low-pressure environments by quantifying how the thresholds and the intensity of dust entrainment produced by rotor downwash evolve as ambient pressure is stepped from Earthlike toward Mars-like conditions. In other words, the work questions how the minimum surface shear required to start motion, and the strength of the dust once moving, change as the atmosphere thins....