速度矢量滚转的运动学及气动力分析

速度矢量滚转定义为飞机在保持定常迎角的情况下,围绕其瞬时速度矢量所产生的无侧滑、速度保持为常值的旋转运动。对于典型的战术飞机,最大俯仰力矩是飞机方位的函数,在水平轨迹中出现在倾斜90°的情况,此时飞机的滚转速率达到峰值,迎角超过45°。最大滚转力矩依赖于滚转模态时间常数。对于较小的滚转时间常数（快速响应）,最大滚转力矩出现在最大滚转加速度、零迎角,基本与飞机的方位无关;对于较大的滚转时间常数,最大滚转力矩出现在最大滚转速率、迎角最大、倾斜角180°的水平飞行中。最大的航向力矩出现在最大滚转加速度、迎角最大时,基本与飞机的方位无关。

Kinematics and Aerodynamics of the Velocity Vector Roll

The velocity vector roll is defined as angular rotation of airplane about its instantaneous velocity vector, constrained to be performed at constant angle-of-attack, no sideslip, and constant velocity. It is shown, for representative tactical airplanes, the conditions of maximum pitching moment are strongly a function of the orientation of airplane, occurring at about 90° of bank in a level trajectory. Maximum required pitching moment occurs at peak roll rate and is achieved at an angle- of-attack in excess 45°. The conditions for maximum rolling moment depend on the value of the roll mode time constant. For a small roll constant （fast response） the maximum rolling moment occurs at maximum roll acceleration and zero angle-of-attack, largely independent of airplane orientation; for a large time constant, maximum rolling moment occurs at maximum roll rate, at maximum angle- of-attack, and 180° of bank in level flight. The maximum yawing moment occurs at maximum roll acceleration, maximum angle-of-attack, and largely independent of airplane orientation.