【作者】 陈健；

【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， 2006， 硕士

【摘要】 本文采用数值仿真和试验两种方法对多喷嘴超声速引射器进行了研究。首先对二维构型的超声速引射器进行了数值计算,研究了零二次流和带二次流时的流场结构,同时对影响其启动性能和引射性能的因素如引射马赫数、混合室收缩角等进行了分析。其次对试验件的内流场进行了三维数值仿真,仿真结果与试验数据比较吻合。在此基础上,分析得到:在混合室前段多股超声速引射气流相互撞击所造成的能量损失是造成该型引射器启动困难的主要原因;采用多个引射喷嘴使一、二次流的混合面积大大增加,改善了引射器的引射性能。试验方面则探讨了引射喷嘴的安装构型、混合室收缩比等因素对多喷嘴超声速引射器启动性能的影响,得到影响该型超声速引射器启动性能的一些结论;提出了利用二次流对一次流的“助推”作用来改善引射器启动性能的方法;分析了一次流总压和引射喷嘴安装构型对引射器引射能力的影响。结果表明:较低的一次流总压能够更好地满足更低总压的二次流的引射需要;合理的喷嘴安装构型意味着更高的引射性能。更多还原

【Abstract】 The CFD and experimental methods were introduced to study the multi-nozzle supersonic ejector.Firstly, the flow-field of a two dimensional ejector with and without induced flow was simulated, the key parameters affecting the starting performance and ejecting performance, such as the primary flow mach number, were analyzed. The 3-D numerical results approximately agreed with the experiment data. At the same time, the following conclusions could be drawn: the flow loss caused by the collision of multi-primary flow was the chief reason for difficulties in starting of the ejector; by increasing the mixing area, improved ejecting performance could be obtained by multi-nozzle.The influences of ejecting-nozzle assembling configuration and the contraction ratio of mixing chamber on the starting performance were studied in detail, and some valuable conclusions could be drawn. It was found that the secondary-flow could act as a“booster”, which helped to improve starting performance of the multi-nozzle ejector. Moreover, it was discovered that the lower the primary flow total pressure, the better for the secondary flow with lower total pressure to be ejected; and a reasonable ejecting-nozzle assembling configuration meant good performance for multi-nozzle ejector.更多还原