Affiliation of Author(s):航空学院
Journal:Aerosp Sci Technol
Abstract:A numerical method based on Reynolds Averaged Navier–Stokes (RANS) equations and moving overset mesh technique is developed to simulate the aerodynamics of Harrington rotor-2. A high-efficient trim model for hover is presented and coupled into the numerical method and the “delta trim arithmetic” is implemented to simplify the calculation of Jacobian matrix. Validation cases are computed, showing reasonably coincident with the available experimental data. Hover cases of different thrust coefficients with torque-balanced are conducted. Specially, zero-lift and one-rotor-stay cases are set for a better understanding of the interaction mechanism. Results indicate that the temporal thrusts of the coaxial rotor show a variation of gradually increasing and sharply decreasing. Different from the previous work, the fluctuation features are mainly explained by strong-weak “induction effect” and impulsive “overlap effect” caused by the interaction of wakes and bound vortexes of coaxial rotor. At a positive attack angle, the induction and overlap effects are more evident for the upper rotor because the induced flow is stronger above the blade than that below it. The first impulse of thrust caused by overlap effect takes place at about 3° azimuth after the alignment of the blades for present cases, as the upper and lower blades meet in a rotating way. © 2018 Elsevier Masson SAS
ISSN No.:1270-9638
Translation or Not:no
Date of Publication:2019-01-01
Co-author:Qi, Haotian,Lu, Congling,syj
Correspondence Author:xgh
Date of Publication:2019-01-01