倾转四旋翼飞行器倾转过渡走廊分析方法

针对倾转四旋翼（QTR）飞行器过渡飞行中的变速、变体特点，提出了一种确定倾转四旋翼飞行器倾转过渡走廊的方法，该方法从飞行力学角度用机翼升力特性限制低速和高速边界，以单旋翼可用功率限制高速边界。所提方法确定了无周期变距的倾转四旋翼飞行器样机倾转过渡走廊，并分析了其在倾转过渡飞行中不同机体迎角下各气动部件的气动力以及前后旋翼需用功率随飞行速度的变化规律。结果表明:倾转四旋翼飞行器在小机体迎角下倾转优于在大机体迎角下倾转；各气动部件提供的垂向力占比会随着机体迎角的改变而变化；机翼升力特性高速边界和单旋翼功率限制边界共同组成了倾转四旋翼飞行器倾转过渡走廊的高速边界；单旋翼可用功率限制边界比总可用功率限制边界更严格。 

Analysis method for conversion corridor of quad tilt rotor aircraft

For flight's characteristics of morphing and speed change in the conversion mode of Quad Tilt Rotor (QTR) aircraft, a comprehensive method based on flight dynamics model is proposed to calculate the conversion corridor of QTR aircraft. In this method, the boundary of lower speed and upper speed are limited by the lift characteristic of wing, and the upper conversion boundary is limited by the available power of the single rotor. The proposed method was used to determine the conversion corridor of the example QTR aircraft without cyclic pitch control, and to analyze the variation of aerodynamic force of pneumatic components and front and rear rotor power with forward speed under different angles of attack of fuselage. The results show that the QTR aircraft is superior in tilting at small angles of attack of fuselage. The vertical force ratio provided by each pneumatic component would change with the angles of attack of fuselage. The upper speed boundary of the conversion corridor of QTR aircraft is composed of the upper speed boundary of the wing lift characteristic and the limit boundary of single rotor power. The available power limit boundary of single rotor is stricter than the total available power limit boundary.