Atmospheric winds and their implications for microair vehicles

Simon Watkins, Juliette Milbank, Benjamin J. Loxton, William H. Melbourne

Research output: Contribution to journalArticleResearchpeer-review

130 Citations (Scopus)

Abstract

Major challenges to low speed microflight are the transient and time-averaged velocities arising from the atmospheric boundary layer, particularly turbulence a few meters above the ground. In this paper, prior work on the temporal and spatial characteristics of the atmospheric boundary layer close to the ground, and the relative turbulence as perceived by a moving craft, are considered. New measurements are described that document the time-averaged and transient velocities at a height of 4 m above the ground. These were made using a bank of four multihole pressure probes laterally separated by 150 and 50 mm on a mast above a test car. Transient flow pitch angles were investigated and it was found that the overall variation with lateral separation decreased relatively slowly with reducing separation, but that both this and the pitch angle coherence may be described nondimensionally. As the slow decrease in pitch variation with lateral spacing implies that the roll inputs arising from vertical fluctuations would increase with reducing span, it is speculated that increasingly active and authoritative control systems are required.

Original languageEnglish
Pages (from-to)2591-2600
Number of pages10
JournalAIAA Journal
Volume44
Issue number11
DOIs
Publication statusPublished - 1 Nov 2006

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