Theoretical and Numerical Study of Asymmetric Unsteady Lex and Slender-Wing Vortices Including Breakdown.

Abstract

The following final report documents the accomplishments made under AFOSR Grant F49620-92-J-9105 for the period starting January 1, 1992 and ending September 30, 1995. During this time, progress was made in better understanding the spiral vortex breakdown phenomenon. A theoretical model of vortex breakdown was developed illustrating the self-induced cause-and-effect nature of the breakdown spiral in sustaining its geometry in an adverse pressure field. From this study a geometric compatibility condition was discovered in the form of a non-dimensional circulation strength. Experiments were conducted to experimentally confirm this geometric compatibility condition. An isolated vortex was subjected to two breakdown-inducing flowfields; the first consisted of a flow obstruction, and the second consisted of a pair of counter-rotating cylinders. The geometric compatibility condition was found to exist for the resulting spiral vortex breakdown from both of the experiments. Three papers were written and presented on this study at several AIAA Applied Aerodynamics conferences, and a journal paper is currently under review. Also, an abstract was submitted in October, 1995 for an AIAA Applied Aerodynamics conference in 1996.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1995
Accession Number
ADA311347

Entities

People

  • E. J. Jumper
  • K. Cheung
  • R. C. Nelson

Organizations

  • University of Notre Dame

Tags

Communities of Interest

  • Air Platforms
  • Space

DTIC Thesaurus Topics

  • Abstracts
  • Aerodynamic Configurations
  • Aerodynamics
  • Delta Wings
  • Diameters
  • Filaments
  • Flow
  • Flow Fields
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Mechanics
  • Geometry
  • Measurement
  • Mechanics
  • Pressure Gradients
  • Radial Velocity
  • Vortex Generators

Fields of Study

  • Physics

Readers

  • Fluid Mechanics and Fluid Dynamics.
  • Systems Analysis and Design
  • Technical Research and Report Writing.