Multidisciplinary Analysis of a Lifting Body Launch Vehicle
Multidisciplinary Analysis of a Lifting Body Launch Vehicle
复制标题
升力体运载火箭的多学科分析
DOI：
10.2514/2.3880
复制
发表时间：
2002
期刊：
影响因子：
--
通讯作者：
R. Lepsch
中科院分区：
文献类型：
--
作者：
Paul V. Tartabini;K. Wurster;J. Korte;R. Lepsch
作为X-33项目第二阶段的一部分，NASA选择了一种集成的升力体/气动发动机配置作为研究运载工具，用于单级轨道可重复使用运载工具的概念分析。在概念设计过程的早期阶段，NASA兰利研究中心的一个团队参与了对一些提议的飞行器配置的筛选和评估。支持这些研究的性能分析是为了评估车辆的起重能力、线性气动发动机和金属热保护系统对车辆重量和性能的影响。这些性能研究以多学科的方式进行，将轨迹优化与重量估计和气动热分析工具间接联系起来。这种方法是必要的，以开发优化的上升和进入轨迹，满足所有车辆的设计约束。当飞行器在飞行过程中沿升力轨迹飞行并改变发动机混合比时，爬升性能得到了显著改善。此外，通过调整总氧化剂-燃料和升空推重比，空重也有可能大幅减少。然而，必须改变最佳的上升飞行轮廓，以确保飞行器可以仅使用气动发动机的气流转向能力来调整俯仰。同样，最优的进入轨迹必须在满足横向距离要求的同时，满足热保护系统的升温速率和过渡约束。
As part of phase 2 of the X-33 Program, NASA selected an integrated lifting body/aerospike engine configuration as the study vehicle for the conceptual analysis of a single-stage-to-orbit reusable launch vehicle. A team at NASA Langley Research Center participated in the screening and evaluation of a number of proposed vehicle configurations in the early phases of the conceptual design process. The performance analyses that supported these studies were conducted to assess the effect of the vehicle's lifting capability, linear aerospike engine, and metallic thermal protection system on the weight and performance of the vehicle. These performance studies were conducted in a multidisciplinary fashion that indirectly linked the trajectory optimization with weight estimation and aerothermal analysis tools. This approach was necessary to develop optimized ascent and entry trajectories that met all vehicle design constraints. Significant improvements in ascent performance were achieved when the vehicle flew a lifting trajectory and varied the engine mixture ratio during flight. Also, a considerable reduction in empty weight was possible by adjusting the total oxidizer-to-fuel and liftoff thrust-to-weight ratios. However, the optimal ascent flight profile had to be altered to ensure that the vehicle could be trimmed in pitch using only the flow diverting capability of the aerospike engine. Likewise, the optimal entry trajectory had to be tailored to meet thermal protection system heating rate and transition constraints while satisfying a crossrange requirement.