直升机机动飞行对尾传动轴临界转速的影响

Influence of a helicopter's maneuvering flight on critical speed of its tail drive shaft

直升机的平动分量和尾传动轴的位置参数均不影响传动轴的临界转速,仅直升机的转动分量对传动轴临界转速产生影响。通过几种典型机动飞行分析了直升机各转动分量对尾传动轴临界转速的影响。结果表明:偏航角速度与水平轴的临界转速近似呈抛物线关系,而与尾斜轴的临界转速近似呈线性关系且为左右对称图形;随着尾斜轴倾斜角的增大,对称轴向左偏移;俯仰角速度对尾传动轴临界转速的影响与偏航角速度相同;横滚角速度与水平轴和尾斜轴临界转速之间均呈线性关系,且随尾斜轴倾斜角的增大,对称轴向右偏移;传动轴第二阶临界转速变化曲线的对称轴对应角速度大小近似为第一阶临界转速时的16倍。

All translational motion components of a helicopter and position parameters of its tail drive shaft do not affect critical speeds of its tail drive shaft,and only rotating motion components of the helicopter affect critical speeds of its tail drive shaft.The influences of rotating motion components of a helicopter on critical speeds of its tail drive shaft were analyzed.The results showed that the yaw angular velocity versus the critical speed of the horizontal drive shaft reveals a relation of parabola,while the yaw angular velocity versus the critical speed of the oblique tail drive shaft is a linear relation and the relation curve is symmetrical;the symmetry axis offsets to the left with increase in the inclination angle of the oblique tail drive shaft;the influence of the pitching angular velocity on critical speeds of the tail drive shaft is the same as that of the yaw angular velocity;the relations' between the rolling angular velocity and critical speeds of the horizontal drive shaft and the oblique tail drive shaft are a linear relation,and the symmetry axis offsets to the right with increase in the inclination angle of the oblique tail drive shaft;the angular velocity corresponding to the symmetric axis of the second-order critical speed curve of the drive shaft is about 16 times of the first-order critical speed.