Aerodynamic and acoustic analysis of helicopter main rotor blade tips in hover

Purpose The design of main rotor blade tips is of interest to helicopter manufactures since the tip details affect the performance and acoustics of the rotor. The paper aims to discuss this issue. Design/methodology/approach In this paper, computation fluid dynamics is used to simulate the flow around hovering helicopter blades with different tip designs. For each type of blade tip a parametric study on the shape is also conducted for comparison calculations were performed the constant rotor thrust condition. The collective pitch and the cone angles of the blades were determined by at an iterative trimming process. Findings Analysis of the distributed blade loads shows that the tip geometry has a significant influence on aerodynamics and aeroacoustics especially for stations where blade loading is high. Originality/value The aeroacoustic characteristics of the rotors were obtained using Ffowcs Williams-Hawkings equations.