【作者】 李杰；

【导师】 吴先宇；

【作者基本信息】 国防科技大学 ， 航空宇航科学与技术， 2017， 硕士

【摘要】 再生冷却/膨胀循环超燃冲压发动机系统方案是解决高超声速飞行器长时间工作问题的有效途径。本文针对膨胀循环超燃冲压发动机燃料供应系统超临界/裂解态煤油涡轮泵组件,采用理论分析与数值仿真相结合的方法,对其参数敏感性及匹配特性进行了深入地研究。首先,对膨胀循环超燃冲压发动机超临界/裂解态煤油涡轮泵进行了方案设计。综合考虑超燃冲压发动机的结构布局及工作特点,分别建立了小流量低比转速离心泵和低压比单级冲击式涡轮的设计方法,根据涡轮泵技术指标进行设计计算并获得了构型参数。其次,建立了超临界煤油涡轮泵的数值仿真流程及方法,通过建立涡轮泵三维模型、计算域网格生成与数值求解,获得了涡轮泵的性能参数,对涡轮泵的设计合理性进行了验证。结果表明:涡轮泵设计方案满足设计要求,涡轮能够为离心泵提供充足的轴功率;离心泵流场流线较为理想,隔舌处未出现漩涡,能够为液态煤油提供稳定的增压功率。然后,经试验设计与高精度数值仿真,建立了涡轮泵运行特性数据库并构建了RBF神经网络响应面模型;基于响应面方法与参数敏感性分析方法并结合数值仿真模型,对超临界煤油涡轮泵参数敏感性进行了深入地研究,主要包括交互效应分析、输入变量对性能响应影响的Pareto分布、多目标Pareto最优前沿分析等,获得了超临界煤油涡轮泵性能指标参数的主要影响因素。最后,采用多目标优化方法为辅助手段,建立了超临界煤油涡轮泵匹配优化模型,对其匹配特性进行了深入地研究,获得了涡轮泵设计点下的最优匹配工况;在非设计点下,获得了涡轮可调量(工质入口压力、质量流量和温度)与系统匹配特性的二阶多项式响应面模型,为涡轮泵试验研究和匹配控制提供了参考依据。论文研究成果为进一步开展膨胀循环超燃冲压发动机起动过程非线性力/热耦合机理研究和发动机综合设计与系统集成技术发展奠定重要的理论与应用基础。更多还原

【Abstract】 The system of scramjet with regeneration cooling and expansion cycle is an effective way to solve the long time work problem of hypersonic vehicle.According to the supercritical kerosene turbopump components of fuel supply system of scramjet with expansion cycle,the parameter sensitivity and matching characteristics were studied by using the combination methods of theoretical analysis and numerical simulation.Firstly,the scheme of the supercritical kerosene turbopump of scramjet with expansion cycle was designed.Considering the structure layout and working characteristics of scramjet,the design methods of centrifugal pump with low flow and low specific speed and single stage impact turbine with low pressure ratio were established respectively.The design parameters were calculated and the configuration parameters were obtained,according to the technical spcifications of turbopump.Secondly,the numerical simulation process and methods of supercritical kerosene turbopump were established.The performance parameters of turbopump were obtained by establishing 3D model,computing mesh generation and numerical solution,and the rationality of design was verified.The results show that the design scheme of turbopump meets the design requirements.The turbine can provide sufficient axial power for the centrifugal pump.The streamline of flow field of centrifugal pump is ideal and there is no vortex at the tongue,which can provide stable supercharging power for liquid kerosene.Then,the operation characteristics database and RBF neural network response surface model of turbopump were established by using DOE and high precision numerical simulation.Based on response surface method and parameter sensitivity analysis method,combined with the numerical simulation model,the parameter sensitivity of supercritical kerosene turbopump was deeply studied,including the interaction effect analysis,the Pareto distribution of influence of input variables on performance response and the multi-objective Pareto optimal frontier analysis etc.The main factors which affect the performance parameters of supercritical kerosene turbopump were obtained.Finally,by using the multi-objective optimization method,a matching optimization model for supercritical turbopump was established and the matching characteristics were deeply studied.The optimal matching condition was obtained at the design point of the turbopump.At the non design point,the two order polynomial response surface model of the matching characteristics of the turbine adjustable variables(inlet pressure,mass flow rate and temperature of working fluids)and the system was obtained,which provides a reference for the experimental research and matching control of the turbopump.The research results of thesis lay an important theoretical and practical foundation for further study on non-linear coupling mechanism of dynamics/thermodynamics of scramjet with expansion cycle during start-up process and development of engine integrated design and system integration technology.更多还原