Accession Number:

ADA592861

Title:

Multidisciplinary Investigation of Unsteady Aerodynamics and Flight Dynamics in Rapidly Maneuvering Micro Air Vehicles: Theory, Laboratory and Flight Experiments

Descriptive Note:

Final rept. Sep 2010-Aug 2013

Corporate Author:

ARIZONA UNIV TUCSON

Personal Author(s):

Report Date:

2013-11-13

Pagination or Media Count:

136.0

Abstract:

The report summarizes wind tunnel studies of flapping wings of locusts and several artificial wings. The stroke-averaged lift and horizontal force are measured in a wind tunnel at an angle of attack varying from horizontal to hovering positions. It is found that for high angles of attack, flapping wings do not exhibit the typical abrupt stall seen with fixed wings. Based on high-speed video data, a theoretical analysis of the flapping wings is performed using the discrete vortex method. It is found that the inertial component is dominant in the normal force coefficient in the studied problem. A normal component of the acceleration of the wings trailing edge is introduced as a kinematic parameter. The report also focuses on transition performance of fixed-wing aircraft with vertical takeoff and landing capabilities. Obtained results show that rapid-pitching efficiency curves converge on steady efficiency curves. From 30 to 70 degrees, efficiency is virtually independent of pitching-rate, throttle-setting, and elevator deflection.

Subject Categories:

  • Aerodynamics
  • Pilotless Aircraft
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE