Design of transition attitude for tilt wing/rotor aircraft
Aiming at the complicated tilt transition configuration change process of tiltrotor aircraft with tilt wing segment,a calculation method of high-speed segment tilt corridor boundary based on blade element momentum theory is proposed.The calculation model of the transition corridor is established by limiting the wing stall at low speed and the rotor available power at high speed.The difference between the transition corridor of traditional tiltrotor and tilt wing/rotor aircraft is compared.The forward flight speed,fuselage angle of attack,and rotor pitch angle in tilt transition state are compared and analyzed.The results show that the tilt wing/rotor aircraft with a tilt wing segment has a narrower tilt corridor.Compared with the traditional tiltrotor aircraft,the tilt speed boundary of the rotorcraft with a tilt wing segment accounting for 1/3 of the span at the nacelle angle of 0°is reduced from 39～57 m/s to 41.7～51.2 m/s,which makes the tilt control more difficult;At the earlier stage of the tilt process when the nacelle angle is greater than 45°,at the same forward flight speed and nacelle tilt angle,the angle of attack of the body of the tilt wing/rotor aircraft decreases by about 2°,and the rotor pitch angle increases by 1°～4°.With the completion of the tilt transition,the attitude difference between the two aircrafts gradually decreases.
tiltrotor aircrafttilt wingtilt corridortilt transition attitudeblade element momentum theory
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万方数据
