Suppression of Vortex-Induced Vibrations for Elliptical Cylinders Using Mixed Convection

Abstract

Transverse vortex-induced vibrations (VIVs) of a 2-D, elliptic cylinder with various aspect ratios and stiffness are studied. The amplitude of transverse motion due to VIVs can be reduced as the thermal control parameter, the Richardson number (Ri), increases. Complete suppression is achieved when Ri is above a critical value. This critical Ri depends on both body-to-fluid density, aspect ratio, and structural stiffness. The study includes finding the lock-in regime for each aspect ratio, where the vibrational amplitude is at a maximum. Bodies at lock-in require a higher critical Ri to suppress VIV than either rigid or flexible structures; however, the gap between the critical Ris decreases with an increase in aspect ratio. Drag experienced by the body is also studied. A maximum drag reduction of 44% was found for an aspect ratio of 2 at the critical Richardson number.

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Document Details

Document Type
Technical Report
Publication Date
Mar 22, 2018
Accession Number
AD1056562

Entities

People

  • Jeffrey A. Desroches

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Force
  • Boundary Layer
  • Buoyancy
  • Computational Fluid Dynamics
  • Convection
  • Drag Reduction
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Flow
  • Geometric Forms
  • Geometry
  • Heat Transfer
  • Mechanical Properties
  • Richardson Number
  • Three Dimensional
  • Turbulent Mixing
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Aerodynamics/Aeronautics.
  • Maritime and Naval Warfare Studies
  • Structural Dynamics.