单轨火箭橇-发动机一体化设计

Integrated design of monorail rocket sled and motor

针对传统单轨火箭橇系统零部件附加质量过高的问题,提出了一种由发动机和滑靴组成的箭橇一体化结构,采用三维欧拉-伯努利梁单元对火箭橇系统进行离散,对滑靴位置做寻优计算,发现中滑靴处于前后滑靴的中间位置时,系统振动量最小,位置分布最优。设计了3种滑靴与发动机壳体连接的方案:(1)滑靴通过锯齿形焊缝与发动机壳体包覆连接,(2)发动机壳体直接堆放在滑靴靴体上,(3)滑靴通过支撑板过渡件与发动机壳体连接。采用橇-轨耦合动力学方法计算方案2和方案3的在轨安全性,方案3的火箭橇系统力学环境更优,其系统附加质量比传统单轨橇降低了73%。最后,开展了箭橇一体化验证试验,验证了箭橇一体化设计方案的合理性。

The solid rocket motor is the only power source of the system in the rocket sled test,the traditional monorail rocket sled generally consists of the rocket motor,the motor mounting components,the reinforced longitudinal beam and the slippers,in which only the test object and the motor charge are effective mass,while the rest of the structures are additional mass,so reducing the additional mass can improve the thrust-to-weight ratio of the rocket sled system.In response to the problem of excessive mass added to the components of the conventional monorail rocket sled system,an integrated rocket sled and motor structure consisting of motor and slippers is proposed.The three-dimensional Euler-Bernoulli beam unit is used to discretize the rocket sled system and obtain the optimal distribution position of the slippers,then it is found that the vibration is minimized when the middle slipper is located between the front slipper and the back slipper.Three options for connecting the slipper to the motor housing are designed:in the first option the slipper is wrapped and connected to the motor housing by serrated welds;in the second one the motor housing is stacked directly on the slipper body;and in the third one the motor housing is connected to the slipper by supported transition plates.A comparative analysis of the on-rail safety of the latter two options is performed using the sled-rail coupling dynamics method,which indicates that the mechanical environment of the integrated rocket sled is better when the sled slippers and the motor housing are connected by the supported plates as transition structures,and the additional mass of the system is reduced by 73%compared to that of the traditional monorail sled.Finally,the validation test of the integrated motor with sled validation test was implemented and the collected data were analyzed,showing that:the integrated motor with sled proposed in this paper is reasonable and feasible,and the motor vibration level is comparable to that of the traditional rocket sled.