GEOMETRIC MODELING OF PROPELLERS AND VALIDATION OF AERODYNAMIC COEFFICIENTS VIA BEMT

Resumo

Advances on aeronautical sector demand research in all areas involved in the project. This
includes the aerodynamic analysis of propellers, since these are used to generate the necessary thrust to
move the airplane, absorbing to the best possible way the supplied power. Among the analytical theories,
those of Theodorsen [1] and Adkins and Liebeck [2] are notable. These theories are denominated blade

element momentum theory (BEMT). The interest in these study in the UFJF was encouraged by the Aero-
design Team (Microraptor), which participates annually in the SAE BRASIL AeroDesign competitions.

In these competitions, the team develop an aircraft, from initial design to construction and testing. In this
context, the present work proposes the study of a propeller chosen by the team for the 2019 season. The
study consists of the geometric modeling of this propeller and subsequent calculation of the aerodynamic
parameters through BEMT model. The necessary data was provided by the manufacturer, and also via
a 3D scanner. The aerodynamic coefficients of the profiles were obtained using the XFOIL program,
developed by Drela [3]. Subsequently, for the calculations of thrust, power and efficiency coefficients,
the QPROP Program, also developed by Drela [4], was used and applies the BEMT methodology. It is

possible to obtain satisfactory values of the traction generated by the propeller, validating both the geo-
metric and the analysis methodology with wind tunnel results. After validation, the power and propeller

efficiency curves were generated, certifying their use for the flight envelope.