Longitudinal aerodynamics of rapidly pitching fixed-wing micro air vehicles

Ryan Randall, Sergey V Shkarayev, Gregg Abate, Judson Babcock

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Some fixed-wing vertical-takeoff-and-landing aircraft can transition between two flight modes: forward flight and near-hover. This study was conducted to improve the transition performance of such vehicles. The experimental model consists of a rigid Zimmerman wing and a propulsion system with contra-rotating propellers. It was rapidly pitched about its aerodynamic center at an average freestream Reynolds number of 86,000. Five nondimensional pitching rates were used, along with two elevator deflections and three propulsive settings. The model was tested statically, and several observations were made. At constant throttle setting, from 20 to 70 deg, both advance ratio and thrust coefficient increase linearly with angle of attack. Higher throttle setting results in greater stall delay, causing the maximum lift coefficient to increase. When throttle setting increases, lift and drag coefficients increase throughout the tested angle-of-attack domain. Rapid-pitching tests showed that nose-up pitching delays stall and nose-down pitching hastens it. Lift and drag coefficients generally increase with positive pitching rate and decrease with negative pitching rate. Wing aerodynamic efficiency is virtually independent of throttle setting, elevator deflection, and pitching rate between 30 and 70 deg angle of attack. The propulsion system is not sensitive to rapid pitching with regard to thrust, normal force, or propulsive moment.

Original languageEnglish (US)
Pages (from-to)453-471
Number of pages19
JournalJournal of Aircraft
Volume49
Issue number2
DOIs
StatePublished - Mar 2012

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Micro air vehicle (MAV)
Fixed wings
Angle of attack
Aerodynamics
Elevators
Drag coefficient
Propulsion
Rigid wings
VTOL/STOL aircraft
Propellers
Reynolds number

ASJC Scopus subject areas

  • Aerospace Engineering

Cite this

Longitudinal aerodynamics of rapidly pitching fixed-wing micro air vehicles. / Randall, Ryan; Shkarayev, Sergey V; Abate, Gregg; Babcock, Judson.

In: Journal of Aircraft, Vol. 49, No. 2, 03.2012, p. 453-471.

Research output: Contribution to journalArticle

Randall, Ryan ; Shkarayev, Sergey V ; Abate, Gregg ; Babcock, Judson. / Longitudinal aerodynamics of rapidly pitching fixed-wing micro air vehicles. In: Journal of Aircraft. 2012 ; Vol. 49, No. 2. pp. 453-471.
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