Modelling, analysis and experimental study of the prop-rotor of vertical/short-take-off and landing aircraft

Abstract

The main objective of this work is to characterise the prop-rotor of V/STOL (Vertical/short-take-off and landing) aircraft in various operating conditions, especially in transition flight. To this end, a BET (Blade element theory) based analytic model/tool with a low computational cost has been built to predict the aerodynamic performance of the prop-rotor. This BET-based model can predict prop-rotor thrust, torque, normal force, and yaw moment as well as their corresponding 1P load (once-per-revolution load on the single blade) regarding oblique flow. This model is verified and shows good consistency with the wind tunnel experimental data and CFD simulation results. Furthermore, by using this BET model/tool, the effects of axial advance ratio, tilt angle and collective pitch angle on these component loads on the prop-rotor are explored. Moreover, the effects of these variables on the vibratory amplitudes of the 1P load on the single blade and 3P harmonic loads on the prop-rotor due to inclined flow are presented as well.