The Nebulous Art of Using Wind Tunnel Aerofoil Data for Predicting Rotor Performance

Abstract

The objective of this study was threefold: to evaluate different two-dimensional S809 aerofoil data sets in the prediction of rotor performance; to compare blade element momentum rotor predicted results with lifting surface, prescribed wake results; and to compare the NASAAmes combined experiment rotor measured data with the two different performance prediction methods. The S809 aerofoil data sets evaluated included those from Delft University of Technology, Ohio State University and Colorado State University. Substantial differences in prediction performance resulted from the different two-dimensional aerofoil data sets. Predicted performance comparison with NASA Ames data documents shortcomings of these methods and recommends the use of the lifting surface, prescribed wake method over blade element momentum theory for future analytical improvements.