Aerodynamic interaction characteristics analysis of intermeshing-rotor fuselage in hover

Abstract

Abstract To study the interference characteristics of the intermeshing-rotor fuselage, a numerical simulation method for the flow field of a crossed twin-rotor helicopter in a hovering state is established based on the lattice Boltzmann method. The effectiveness of the proposed numerical simulation method is first verified by the ROBIN helicopter rotor/fuselage interference example. Then, taking the simplified JZ-60 rotor and S-97 helicopter fuselage as the research objects, the aerodynamic interference characteristics of the intermeshing rotor and the fuselage are investigated, and the aerodynamic interference law between the two under the hovering state is obtained. The results show that the intermeshing rotor has periodic tension fluctuation, and the fuselage interference leads to about a 4% increase in the total tension of the rotor. The maximum hovering efficiency increases by about 5%, and the larger the tension coefficient is, the larger the fuselage gains on the hovering efficiency is. The fuselage generates periodic negative lift and lateral force under the influence of the rotor. The hovering efficiency gains of the rotor mainly originate from the increases of the blade lift coefficients in the vicinity of the azimuth angles of 0° and 180°. The rotor is in the range of 0.5° and 180°, which has the strongest interference effect on the fuselage near 0.6 R and -0.7 R.