A more comprehensive database for propeller performance validations at low Reynolds numbers
Validation is the essential process of evaluating the precision and reliability of analytical or computational solutions. In this dissertation, a series of comprehensive propeller wind tunnel tests were designed for validation of propeller design and analysis techniques. This work focused primarily on small propellers operating at lower Reynolds numbers in the range of 90,000 to 120,000, which is particularly helpful for unmanned aerial vehicle applications. Extensive propeller and experimental apparatus geometries along with test section spatial dimensionality are described. An open-source computer-aided design (CAD) method was used to create the propeller blades, nacelle, and spinner surface outlines, aiming for easy reproduction. Two different propeller designs were tested: a simple propeller with a constant pitch-to-diameter ratio, chord length, and thickness; and a complex propeller with a pitch-to-diameter ratio and chord length as a function of blade radius. Both propellers with a variable pitch of five degrees increment were tested at several angle settings. Critical test section flow field and geometry information that can be used as boundary conditions are also presented in this study. In addition to classical propeller performance plots of thrust and torque coefficients and efficiency against the advance ratio, nacelle surface pressure distribution in terms of coefficients and propeller wake survey results are provided. Two different wind tunnels were utilized to evaluate the experimental and facility bias. Known errors, uncertainties, and instrumental accuracies are quantified and presented here.