AN INVESTIGATION OF THE HYBRID LTA HAVING ENDURANCE FOR WIND

(1)利用无线电控制模型研究了具有足够机动性和稳定性的混合型LTA的形成.(2)给出了混合型LTA的两种包络，一种是甜甜圈型，另一种是椭圆形环型。在包络中部的空腔部分设置了两个类似于直升机的转子，甜甜圈型同轴，椭圆形环型串联。为了获得力矩平衡，两个转子的旋转方向是相反的。(3)简单的转子叶片循环变桨距控制不能产生足够的力矩来控制模型的姿态和运动。增加了一个装置，使转子轴的倾斜运动独立于包络。模型的直线和圆周运动可以通过转子轴倾斜的循环变桨距控制来快速控制，同时对同轴式转子的圆周运动增加了差动转子速度控制。(4)在串联式转子模型的基础上增加了两个小的侧转子。但它们产生的扭矩不足以控制信封的滚动运动。为了达到这一目的，需要更大功率的转子。(5)在风洞中测量了两种包络的风洞模型阻力和升力。结果表明，圆柱体的阻力略小于二维圆柱体的阻力，而圆环形圆柱体的阻力略小于椭圆环型。(6)在本文研究结果的基础上，进一步改进了混合圆柱体的结构形式。

(1) The formation of hybrid LTA having maneuvarability and stability sufficient to perform the flight in gusty wind was investigated by means of radio-cotrol models.(2) Two types of envelope of The LTA were presented, one was of doughnut type and another was of elliptic-ring type. Two hericopter-like rotors were set in the cavity portion at the middle of the envelope, coaxially for the doughnut type and tandem for the elliptic-ring type. The direction of rotation of two rotors were taken inversely in order to obtain touque balance.(3) Simple cyclic pitch-control of the rotor-blades was found not to produce the torque sufficient for the control fo attitude and movement of the models. A device was added that enabled tilting motion of the rotor-shafts independently of the envelope. The linear and circular motion of the models could be controlled quickly by the cyclic pitch-control accompanied by the tilting of the rotor shafts, with addition of differential rotor-speed control for circular motion of the coaxialrotor type.(4) Two small side rotors were added to the tandem-rotor type mode. But they produced the torque insufficient to control the rolling motion of the envelope. It has been found that more powerful rotors are needed for that purpose.(5) Drag and Lift of wind-tunnel models of two types of the envelope were measured in an wind tunnel. It has been found that the drag is a little smaller than the drag of the well-known two-dimensional circular column, and the drag of the doughnut type is somewhat smaller than that of the elliptic-ring type.(6) Further improvement of the form of the hybrid LTA will be made, based on the results of the present investigation.