Fluctuating Wind Forces Measured on a Bluff Body Extending from a Cavity

Abstract

The effect of wind forces measured on a bluff body extending from a cavity was investigated. This was accomplished by measuring wind induced vibratory inputs to a plexiglas bluff body model. The model extended from a ground board cavity installed in the AFIT 5-Foot Wind Tunnel. Forces and moments were measured from an 8 element load cell unit built and installed in the base of a plexiglas model. Three different size cavity openings were tested for both a no-rotation and 45 degree rotation referenced to the wind. Data was taken at individual speed points between 55 ft/s and 180 ft/s, producing Reynolds number based on model width in the range of 1.5 x 10 to the 5th power to 5.0 x 10 to the 5th power. Baseline data for a closed cavity configuration was collected and compared to previous studies conducted at the USAF Academy. Force and moment coefficient data are presented, comparing cavity opening and model rotation effects. Results of shedding frequency analysis are presented based on transient data recorded. Keywords: Theses, Flow visualization, Wind tunnels.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1989
Accession Number
ADA216414

Entities

People

  • Brian W. King

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Weapons Technologies

DTIC Thesaurus Topics

  • Boundary Layer
  • Dc Motors
  • Flow Fields
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Frequency
  • Load Cells
  • Measurement
  • Mechanics
  • Modal Analysis
  • Pressure Measurement
  • Resonant Frequency
  • Reynolds Number
  • Three Dimensional
  • Wind Tunnels

Readers

  • Aerodynamics/Aeronautics.
  • Fluid Dynamics.
  • Marine Propulsion Engineering and Naval Architecture