Unsteady flow field measurements using LDV.

Abstract

The primary goal of this thesis was the development of an experimental technique, and supporting software, for the acquisition and analysis of unsteady velocity data generated by an oscillating airfoil. This research was in support of a major investigation of the compressibility effects on dynamic stall . The experimental procedure involved schlieren flow visualization for comparison of steady and unsteady flow fields, and for determination of parameters for further study. Laser Doppler velocimetry was employed for obtaining velocity data in the airfoil wake. For unsteady data, the airfoil was oscillated in pitch about its quarter chord. The data analysis produced wake profile plots representing the flow field disturbed by the airfoil. Results were obtained for steady and unsteady conditions.