【作者】 吴继平；

【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， 2007， 博士

【摘要】 论文以高增压比多喷管超声速引射器为研究对象,系统地研究了超声速引射器的设计理论,建立了固定第二喉道超声速引射器启动性能和引射性能的准二维分析模型,设计了高增压比多喷管超声速引射器,并采用实验与数值仿真相结合的方法系统深入地研究了高增压比多喷管超声速引射器的启动特性和负载匹配特性。通过喷管构型因子的引入统一了中心引射、环形引射和多喷管引射的控制体方程,建立了针对等截面混合引射器、等压混合引射器和可调第二喉道理想引射器的参数优化设计模型,并研究了设计参数对引射性能的影响规律。建立了固定第二喉道引射器完整的启动性能和引射性能准二维分析模型,并系统地研究了引射器设计参数对引射性能的影响。该模型采用特征线分析方法结合Korst再压缩判据计算引射器盲腔压力,结合一维控制体分析方法求解第二喉道极限收缩比、最小启动压比;采用常压湍流混合模型模拟一、二次流之间的混合作用;针对高增压比引射器,对二次流处于壅塞状态时的分析进行了简化。设计了几何结构可调的模型引射器,研究了引射器的启动和不启动过程,提出了判断第二喉道面积过小导致引射器无法启动的判据。根据理论分析结果提出了解决引射器不启动问题的多种方案,并分析了各种方案的优缺点和适用范围。设计了单模块多喷管超声速引射器,建立了单模块超声速引射器实验系统,采用燃气作为一次流工质对引射器的启动性能进行了实验研究。结合数值计算结果,深入地研究了引射喷管安装构型、引射喷管型面、第二喉道收缩比以及引射喷管安装构型与引射管道的匹配等因素对引射器启动性能的影响。结果表明:引射喷管型面和引射喷管安装构型与引射管道的匹配对引射器启动性能影响较大。采用模拟器产生高温二次流对引射器的负载匹配特性进行了研究,结果表明多喷管引射器完全可以满足二次流对引射增压能力和压力匹配能力的需求。系统地研究了一次流总压和总温对引射性能的影响、二次流入口参数对引射性能需求的影响以及引射器几何结构参数对引射增压能力和压力匹配能力的影响。创造性地提出了将二次流作为“助推器”改善多喷管超声速引射器在较低工况下自启动性能的思想。更多还原

【Abstract】 The theory and methods for designing a supersonic ejector were comprehensively examined, a quasi-two-dimensional flow model was established to analyze the start and eject performance of supersonic ejector with a fixed second throat; a high compression ratio multi-nozzle supersonic ejector was designed and constructed; and start and load matching characteristics of the multi-nozzle supersonic ejector were investigated systematically with experimental and numerical methods.With a nozzle configuration factor introduced, the control volume equations for center injection, annular injection and multi-nozzle injection were consolidated; parameter optimization models were established for constant area ejector, and constant pressure ejector and second throat adjustable perfect ejector, respectively. Furthermore, the influences of design parameters on ejector performance were studied.A quasi-two-dimensional flow model was presented to analyze the start and eject performance of an ejector with a fixed second throat, and the influences of design parameters on the start and eject performance were studied. In this model, method of characteristics and Korst recompression criterion were combined to calculate the cell pressure; one dimensional control volume analysis was integrated to iterate the second throat contraction ratio limit and the minimal start pressure ratio; constant pressure turbulent mixing model was used to analyze the mixing effect, and an alternative method was brought up to simplify the calculation for high compression ration ejector.A model ejector with variable geometrical throat was designed, then, the processes of start and unstart were investigated, and a criterion was proposed for the condition that second throat is too small to start. Several resolutions were presented to settle the unstart problem, and the relative merits and the applicability of each resolution were analyzed.A high compression ratio modular multi-nozzle supersonic ejector was designed, and a test facility was established. On the test facility, start performance was researched experimentally, with rocket exhaust being used as primary working medium. The influences of nozzle assemble configuration, nozzle profile, second throat contraction ratio and the coupling of nozzle assemble configuration with ejector duct on the start performance were investigated experimentally and numerically. The results showed that: nozzle profile and the coupling of nozzle assemble configuration and ejector duct have great influence on the ejector start performance.With hot rocket exhaust produced by simulator being used as secondary flow, plentiful experiments were carried out to investigate the characteristics of load matching of the multi-nozzle supersonic ejector, and the results showed that the requirements of secondary flow on the capability of entrainment and pressure matching can be fulfilled by the multi-nozzle supersonic ejector. The effect of primary flow total pressure and total temperature on the eject performance, the influences of secondary flow inlet condition on the requirement of eject performance, and the influences of geometric parameters on the capability of entrainment and pressure matching were investigated. Finally, Secondary flow was suggested to be a booster to improve the start performance under lower operation condition creatively.更多还原