Validation of Vortex Propeller Theory for UAV Design with Uncertainty Analysis

Abstract

The emergence of the field of mini- to meso-scale unmanned aerial vehicle (UAV) design has generated renewed interest in propeller modeling, analysis and design. This paper presents a procedure for deriving the performance of an UAV-scale propeller from geometric measurements using commercially available airfoil modeling software and the vortex theory of airscrew propellers. Vortex theory formulations using the Prandtl tip loss factor as well as the Goldstein circulation function are presented and results are compared to wind-tunnel tests of UAV propellers. The effects of measurement and modeling uncertainties on the performance of the propeller are quantified and propagated through the algorithm using system sensitivity analysis. Nomenclature αL0 = airfoil section zero lift angle of attack β = aerodynamic pitch of the propeller blade relative to αL0 c = propeller section chord CD = drag coefficient CL = lift coefficient