Computational Investigation of Unsteady Low-Reynolds Number Aerodynamics for Micro Air Vehicles

Abstract

A Navier-Stokes equation solver is utilized to investigate the aerodynamics of a flapping airfoil. The roles of plunging and pitching amplitude and frequency, and Strouhal number are studied. For a NACA0012 airfoil at zero geometric angle of attack, chord Reynolds number of 20,000 and at a given plunging frequency, either drag or thrust is produced, depending on the plunging amplitude. When drag is produced, the viscous force dominates the total drag with decreasing influence as the plunging amplitude increases. At the considered plunging amplitude (from 0.0125c to 0.075c), flow history has more influence than the kinematic angle of attack in determining lift. For an airfoil experiencing combined plunge and pitch motion, both thrust and input power increase with the Strouhal number (within the range of 0.03 to 0.5). For the case studied, the thrust is induced by the lift, which follows approximately the curve of kinematic angle of attack. Leading edge vortex moves downstream and interacts with the trailing edge vortex. The impact of a gust on a stationary and flapping airfoil is also studied.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 2007
Accession Number
ADA469572

Entities

People

  • Wei Shyy
  • Youngsheng Lian

Organizations

  • University of Michigan

Tags

Communities of Interest

  • Autonomy
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Aerodynamics
  • Aircrafts
  • Computational Fluid Dynamics
  • Equations
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Hydrodynamics
  • Leading Edges
  • Mach Number
  • Mechanical Engineering
  • Mechanical Properties
  • Micro Air Vehicles
  • Navier Stokes Equations
  • Reynolds Number
  • Strouhal Number
  • Trailing Edges

Fields of Study

  • Physics

Readers

  • Aerodynamics.
  • Fluid Mechanics and Fluid Dynamics.