关键词: 共轴刚性旋翼, 气动干扰, 机身, 试验研究, 悬停

Abstract: Experimental and computation studies were conducted on the aerodynamic interaction between coaxial rigid rotor-fuselage in hover. The influence of fuselage aerodynamic interference on the aerodynamic characteristics of coax-ial rigid rotor were analyzed, as well as the pressure distribution on the fuselage surface under coaxial rigid rotor interference. It is found that the range of high lift areas at the tip of the upper and lower rotor blades increased, and the power coefficients of the rotors reduced at the same tension coefficient with the aerodynamic interaction of the fuselage. The rotor maximum Figure of Merit (FM) increased by about 4.6%. The fuselage generated vertical down-load, which is about 7% of the rotor pull force, with the influence of rotor downwash flow. Excluding vertical down-load on the fuselage, the maximum FM of the rotor will be reduced by about 6% compared to the isolated rotors. Under the aerodynamic interaction of rotor, the fuselage has an upward force moment, which is proportional to the rotor tension coefficient. The surface pressure of the fuselage exhibits an unsteady variation of 4 times the rota-tional frequency.

Key words: Coaxial rigid rotor, Aerodynamic interaction, Fuselage, Test analysis, Hover