Flapping-Wing Propulsion as a Means of Drag Reduction for Light Sailplanes

Abstract

In this paper, flapping-wing propulsion as a means of drag reduction for light sailplanes is investigated numerically. The feasibility of markedly improving minimum sink and L/Dmax performance parameters in light sailplanes by flapping their flexible, high aspect ratio wings at their natural frequencies is considered. Two propulsive systems are explored: a human-powered system that is used to partially offset airframe drag, and a sustainer system that uses an electric motor with sufficient power for limited climb rates. A numerical analysis is conducted using a strip-theory approach with UPOT (Unsteady Potential code) data. Thrust and power coefficients are computed for 2-D sections. 3-D spanwise load factors are applied to calculate total wing thrust production and power consumption. The results show that theoretical drag reduction in excess of 20% and improvements of minimum sink by 24% are possible with a human-powered flapping system.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 2002
Accession Number
ADA407241

Entities

People

  • Brian H. Randall

Organizations

  • Naval Postgraduate School

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Aircrafts
  • Airframes
  • Aspect Ratio
  • Birds
  • Computational Fluid Dynamics
  • Drag
  • Drag Reduction
  • Electric Motors
  • Energy Consumption
  • Fluid Dynamics
  • Frequency
  • Gliders
  • Numerical Analysis
  • Resonant Frequency
  • Three Dimensional
  • Two Dimensional
  • Wing Tips

Fields of Study

  • Physics

Readers

  • Aerodynamics.
  • Aerospace Engineering
  • Computational Fluid Dynamics (CFD)