【作者】 李泽勇；

【导师】 王振国；

【作者基本信息】 国防科学技术大学 ， 航空宇航科学与技术， 2008， 博士

【摘要】 本文以整体式固体火箭冲压发动机为研究对象,紧密结合当前导弹动力系统研制需求,致力于解决当前研制面临的冲压发动机高速巡航性能偏低和导弹机动性不足的突出问题,自主创新提出了新概念组合喷管设计方案及其流量分配调节和推力矢量两项新技术。在导弹飞行全速度范围内,既可实现冲压喷管流量调节,大幅提高冲压发动机高速巡航性能,又可构造出矢量推力,用以实现导弹飞行的直接力控制。本文研究工作不仅具有重大的工程实用价值,而且明确从组合喷管流量分配调节技术取得突破,打破了以往采用固定几何结构单喷管不调节的技术传统,丰富了冲压发动机设计理论,又具有重要的科学理论意义。围绕组合喷管及其流量分配调节和推力矢量技术,本文开展了系统性研究。首先针对当前整体式固体火箭冲压发动机研制及其技术发展状况进行了周到细致的技术分析和总结,指出了喷管不调节造成冲压发动机高速巡航性能大幅损失的严重问题,厘清了其物理流动机制,并追根溯源从设计思想和技术路线上找不足。从而确立了本文研究的技术路线,即以提高冲压发动机的高速巡航性能为重心,采用“高速巡航+敏捷性”组合战术战法,选用简单“十”字形轴对称气动布局,降低飞行控制设计难度。并挖掘进气道整流罩的结构功用,充分利用其内部安装空间,开展了组合喷管与导弹气动外形的保形结构设计。基于冲压发动机工作原理,本文从气体动力学理论出发,引入恰当工程经验和近似处理,以满足初步方案快速工程设计和计算评估为目的,确立了组合喷管及其流量分配调节和推力矢量的理论设计计算方法和分析模型,并运用其开展了组合喷管实例设计和计算分析。不仅定量论证了常规固定几何结构喷管制约冲压发动机性能的机理,而且针对该问题设计出具体的组合喷管方案,细致阐述了其设计过程,定量分析和评估了组合喷管及其流量分配调节的性能优势,还探讨了易于工程实现的冲压喷管调节技术对策和推力矢量构造方式。本文最后还引用先进的CFD数值模拟技术,完成了组合喷管方案的数值验证,揭示了组合喷管流动内蕴的流量分配调节物理机制,证明了本文设计思想和技术路线的正确性,并且修正和弥补了设计理论和计算模型的不足。基于数值模拟,还刻画了组合喷管内部流动的细节特征,揭示出组合喷管与补燃室构成分歧管道导致流动损失的现象,为进一步开展组合喷管方案优化设计提供了指导。特别地,从数值模拟结果中,本文获得了一个非常有实用意义的重要结论:仅需选用最简单的两段调节策略,即在设计点速度以下,辅助喷管全部打开,而高于设计点速度时,辅助喷管全部关闭,采用组合喷管方案就可使整体式固体火箭冲压发动机推力性能大幅提高。对比原有固定几何结构单喷管不调节的方案,本文设计方案在接力点2Ma处,发动机推力同比提高18.51%。在设计点2.8Ma处,同比提高26.57%。3.5Ma高速巡航时,同比提高27.95%,推力系数值从原来的0.5612提高到0.7438,比较可观。足见喷管不调节造成发动机高速巡航性能损失有多大,而采用组合喷管流量分配调节措施弥足了该部分损失,使得冲压发动机同时兼备高的高速巡航性能和良好的低速接力性能。概括起来,本文不仅圆满完成了组合喷管及其流量分配调节和推力矢量技术的原理性设计研究,而且还完成了其技术验证,从而证明该方案不仅理论可行,而且易于工程实现,方案的技术优势明显,工程实用意义大。更多还原

【Abstract】 An innovative conceptual combined nozzle and its two innovative technologies, combined nozzle flow regulation and thrust vector, applicable to solid fuel integral ducted-rocket are presented to solve current ducted-rockets’ deficiencies in high speed cruise performance and maneuverability. Within entire missile speed range, these technologies not only improve thrust performance by regulating nozzle flow, but also realize missile direct thrust control through constructing vectored thrust. Unlike conventional fixed geometry nozzle that can not be regulated, this work made a breakthrough by establishing a combined nozzle flow regulation technology, which not only has great scientific significance by enriching ducted-rocket design theory, but also has great value in engineering applications.Systematic researches on combined nozzle and its flow regulation, as well as thrust vector technologies are carried out in this dissertation. First, by analyzing and summarizing current status of solid fuel integral ducted rocket technology in detail, the problem that unable to regulate nozzle causes severe degradation in ducted rocket high speed cruise performance is identified, and its flow mechanisms are clarified and its causes are traced back to design philosophy and technical approaches. Therefore, technical roadmap of current study, which emphasizes on improving high speed cruise performance, uses high speed cruise and high maneuverability tactic, and adopts simple cruciform axisymmetric configuration to reduce difficulties in flight control design, is established. To fully utilize structural space within inlet cowl, conformal structural design of combined nozzle and missile aerodynamic configuration is also carried out.Based on the working principles of solid fuel ducted rocket and gas dynamics theory, as well as appropriate engineering experiences and approximations, the computation method and analytical model of combined nozzle flow regulation and thrust vector design are established. And design case study is also performed using these models. The mechanisms that conventional fixed geometry nozzle limits ducted rocket performance are demonstrated quantitatively. And the solution, detailed combined nozzle concept, is proposed and discussed. The performance advantages of combined nozzle and its flow regulation are analyzed and evaluated quantitatively also. In addition, easy to implement nozzle regulation strategies and thrust vector construction methods are also explored.Finally, advanced CFD numerical simulations are carried out in design validations, revealing the physic natures of combined nozzle flow and its regulation, proving the correctness of current design idea and technology approach, and correcting minor deficiencies of design theory and computational models. Based on numerical simulations, detailed flow behaviors inside combined nozzle are depicted, and the phenomenon of flow loss caused by combined nozzle and secondary combustion chamber branching is also revealed, providing guides for further optimization.In particular, from simulation results, an important conclusion can be drawn:Only the simplest two stage control strategy, i.e., auxiliary nozzles are fully opened below design speed, and are fully closed above design speed, is required for the combined nozzle concept to significantly improve thrust performance of solid fuel integral ducted rocket. Compared to conventional design, the proposed design improves thrust by 18.51% at Ma 2 relay point, and by 26.57% at Ma 2.8 design point. At Ma 3.5 high speed cruise, the thrust is improved by as high as 27.95%, and thrust coefficient is increased from 0.5612 to 0.7438. It clearly shows the loss caused by unregulatable nozzle. However, this loss can be avoided by the proposed concept, so that the ducted rocket has good performance in both high speed cruise and low speed relay.In conclusion, the principle design studies and technical validations of combined nozzle and its flow regulation, as well as thrust vector technologies are completed successfully. The concept is not only feasible theoretically, but also easy to implement, having great prospects in engineering application.更多还原