Self-Excited Torsional Oscillations of an Arfoil

Author: Levy, Charles Nathaniel

Year: 1945

Degree: Engineer's thesis

Advisor: Dunn, Louis G.

Committee Member: Unknown, Unknown

Option: Aeronautics

DOI: 10.7907/0HEH-TC15

Abstract

This thesis is a report on one phase of a program on the self-excited oscillations of an airfoil. This program was sponsored by the National Advisory Committee for Aeronautics at the California Institute of Technology. This thesis covers the torsional oscillations of an elastically suspended airfoil.

The experimental work consisted of measurements of the amplitude of torsional oscillations of a wing elastically suspended in the airstream of a wind tunnel so as to be capable of torsional oscillations only. The results show that torsional oscillations occur at all velocities above a critical velocity and increase in amplitude with velocity without reaching any apparent limit.

Glauert's theory of the forces on an oscillating airfoil do not agree with the experimental results obtained. This theory indicates that oscillations below the stall will not occur for the values of V/nb studied here, whereas the experiments indicate that oscillations do exist.

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