Citation
Nadal Mora, Vicente J. and Sanz Andres, Angel Pedro and Cuerva Tejero, Alvaro
(2006).
Model of the aerodynamic behavior of a pararotor.
"Journal of Aircraft", v. 46
(n. 3);
pp. 1893-1903.
ISSN 0021-8669.
https://doi.org/10.2514/1.21435.
Abstract
Asimple semi-empirical model for the aerodynamic behavior of a low-aspect ratio pararotor in autorotation at low
Reynolds numbers is presented. The paper is split into three sections: Sec. II deals with the theoretical model
derivation, Sec. III deals with the wind-tunnel measurements needed for tuning the theoretical model, and Sec. IV
deals with the tuning between the theoretical model and the experimental data. The study is focused on the effect of
both the blade pitch angle and the blade roughness and also on the stream velocity, on the rotation velocity, and on the
drag of a model. Flow pattern visualizations have also been performed. The value of the free aerodynamic parameters of the semi-empirical model that produces the best fit with the experimental results agrees with the expected ones for the blades at the test conditions. Finally, the model is able to describe the behavior of a pararotor in
autorotation that rotates fixed to a shaft, validated for a range of blade pitch angles. The movement of the device is
found to be governed by a reduced set of dimensionless parameters.