【作者】 刘泽军；

【导师】 胡小平；

【作者基本信息】 国防科学技术大学 ， 工程热物理， 2009， 硕士

【摘要】 本文以某型上面级液体火箭发动机地面试车引射系统为研究对象,对该引射系统中的超声速环型蒸汽引射器进行了研究。首先根据一维设计理论,在没有考虑蒸汽流动过程中的凝结的条件下,得到了引射器性能的变化规律。接着建立了湿蒸汽凝结流动数值模型,并利用经典实验的结果对该模型进行了数值校验,验证了数值模型的可信度和准确性。随后对超声速环型蒸汽引射器进行了大量的数值仿真计算,得到了不同状态下凝结流场的结构,并且提出了提高引射能力的方法。最后简单讨论了超声速环型蒸汽引射器的启动特性。本文的研究工作完成了如下的主要内容:1、利用引射器的一维设计理论,编写了计算引射器性能参数的程序,探讨了在未考虑蒸汽凝结时工作参数和结构参数变化对超声速引射器性能的影响。计算结果表明:采用较高的引射马赫数、较小的引射系数和喷嘴出口气流方向角,有利于提高引射能力。混合室压缩比Em对引射器的性能有重大影响,在引射器设计过程中应慎重考虑。2、建立了湿蒸汽凝结流动模型,模型的计算结果与C. A. Moses和G. D. Stein实验,以及M. J. Moore实验的数据基本吻合,从而验证了模型的可信度和准确性。3、利用湿蒸汽凝结流动模型对超声速环型蒸汽引射器进行了大量的数值计算。结果表明:引射喷嘴流场由于蒸汽的凝结,使得出口马赫数下降,静压和静温有所提高。采用较低的引射总压和较高的引射总温,可以减少蒸汽的凝结量,提高引射能力;蒸汽的凝结使得引射系数下降,并且引射系数越小,下降的幅度越大。适当地减小收敛比?、面积比?和增大二次喉道的长径比l d ,可以提高总压恢复系数,改善引射器性能。增大引射喷嘴入口蒸汽的过热度,也可以使启动压强降低。更多还原

【Abstract】 Taking a certain type of upper-stage liquid-propellant rocket engine ground test ejector system as the research object, the ejector system of supersonic steam annular ejector was researched in this paper. First, according to one-dimensional design theory, without considering the process of condensing steam flow conditions, the performance of ejector system was studied. Then, the numerical model for wet steam condensation flow was established, quantitative validation of which was accomplished by using the classic experiments. And the structures of flow field while condensating were obtained under different conditions, based on a large number of numerical simulations about supersonic steam annular ejector. Several methods were presented to improve ejector capabilities. Finally, the startup characteristics of the supersonic steam annular ejector were discussed briefly.The main contents are given as follows:1. Base on one-dimensional ejector design theory, the preparation of the calculation ejector performance parameters of the process, the performance of supersonic ejector was studied under different flow parameters and structures (without considering the steam-condensing).The results show that: higher injection Mach number, smaller injection coefficient and smaller nozzle exit flow direction angle were conducive to injection capacity. Mixing chamber compression ratio E m has a significant impact on the ejector performance, which should be considered carefully in design of the ejector.2. Numerical simulation results with wet steam condensation flow model were coincident to the experimental data of C. A. Moses and G. D. Stein, as well as M. J. Moore, which validated the credibility and accuracy of the model.3. A large number of numerical simulations about supersonic steam annular ejector were presented by using wet steam condensation flow model. The results showed that: in ejector nozzle flow field, as Mach number of the exit declined, static pressure and static temperature increased due to vapor condensation. A lower injection pressure and a higher total temperature injection can reduce the amount of steam condensation, thus improve the injection capacity. Injection coefficient decreased because of condensation of steam, and the smaller the injection coefficient, the greater the decrease. Appropriately reducing the convergence ratio ? , area ratio ? and increasing the l d of secondary throat can increase the total pressure recovery coefficient to improve ejector performance. By increasing the entrance overheating degree of the steam ejector nozzle, the start-up pressure can be cut down as well.更多还原