Wind Tunnel Blockage Corrections for Propellers

Abstract

Early in the twentieth century, Glauert developed a still widely used correction methodology for blockage in wind tunnels. Since then, several improvements to this method as well as new methods have been developed. For this thesis, powered propeller data was gathered in two wind tunnels of significantly different size. The Glauert correction, Hackett-Wilsden correction, and one of the newest corrections, developed by Sørensen and Mikkelsen, was applied to the data. Additionally, predictions of the pressure change in the tunnel due to the energy of the propeller were calculated.

The data, when corrected using each method, are essentially identical up to a thrust coefficient of approximately 1.2. Beyond this value, the correction data begins to diverge. The pressure predictions are inaccurate when compared to experimental data and it is suggested that this be an area for further study.