Frequency lock-in phenomenon for self-sustained roll oscillations of rectangular wings undergoing a forced periodic pitching motion

Abstract

The free-to-roll behaviour of rigid and membrane rectangular wings with an aspect ratio of two was studied in wind tunnel experiments conducted at a chord Reynolds number of Rec = 46 000. Self-excited roll oscillations resulting from the fluid-structure interaction were studied in forced sinusoidal pitching motion in order to simulate gust encounters of small air vehicles. For the dynamic pitching cases, the frequency and phase of the self-excited roll oscillations can become synchronized (or locked-in) with the fundamental pitching frequency and its subharmonics. This is believed to be the first documented example of synchronization for this type of fluid-structure interaction. Depending on the amplitude and frequency of excitation (pitching motion), there are regions of decreased roll oscillations, which may be important for the gust response of small vehicles.

Document Details

Document Type
Pub Defense Publication
Publication Date
Nov 01, 2012
Source ID
10.1063/1.4767468

Entities

People

  • Ismet Gursul
  • L. Tregidgo
  • Zhongbao Wang

Organizations

  • Air Force Office of Scientific Research
  • University of Bath

Tags

Readers

  • Aerodynamics/Aeronautics.
  • Control Systems Engineering.