Computational Research of the Main Rotor Steep Descent Modes Based on the Nonlinear Blade Vortex Model

Abstract

The main rotor operation is studied of the Mi-8 single-rotor helicopter in steep descent modes at the rotor angles of attack α_R = 90−30 deg. The study resulted in total and distributed aerodynamic performance, rotor wake patterns and flow patterns. The vortex ring state area is designed based on the result analysis in terms of some features. The calculation results are compared with the experimental data and calculations of other authors.