Experimental Study of a Nozzle Using Fluidic Counterflow for Thrust Vectoring
Experimental Study of a Nozzle Using Fluidic Counterflow for Thrust Vectoring
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DOI：
10.2514/6.1998-3255
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
J. Flamm
中科院分区：
文献类型：
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作者：
J. Flamm
对一种逆流推力矢量喷管方案进行了静态试验研究。这项研究是在美国宇航局兰利研究中心喷气出口试验设施进行的。内部性能特性是在喷嘴压力比（射流总压力与环境压力）为3.5至10.0的范围内确定的。研究了吸气环几何形状和吸气槽高度对喷管性能的影响。在逆流概念中，推力转向是通过在主喷流附近的一个槽内施加真空来实现的，主喷流被一个吸力环所覆盖。根据试验条件和配置，两种流动现象可引导主射流。在一种情况下，真空源在主射流附近产生次级反向流动流。两股逆流之间的剪切层混合并从周围的流体中夹带质量。轴环的存在抑制了质量夹带，并且轴环附近的流动加速，导致轴环上的压力下降。第二种情况类似地工作，除了真空不足以产生逆流流，而是存在同向流。如果在射流顶部或底部不对称地施加吸力，则主射流是矢量的。
A static experimental investigation of a counterflow thrust vectoring nozzle concept was performed. The study was conducted in the NASA Langley Research Center Jet Exit Test Facility. Internal performance characteristics were defined over a nozzle pressure ratio (jet total to ambient) range of 3.5 to 10.0. The effects of suction collar geometry and suction slot height on nozzle performance were examined. In the counterflow concept, thrust vectoring is achieved by applying a vacuum to a slot adjacent to a primary jet that is shrouded by a suction collar. Two flow phenomena work to vector the primary jet depending upon the test conditions and configuration. In one case, the vacuum source creates a secondary reverse flowing stream near the primary jet. The shear layers between the two counterflowing streams mix and entrain mass from the surrounding fluid. The presence of the collar inhibits mass entrainment and the flow near the collar accelerates, causing a drop in pressure on the collar. The second case works similarly except that the vacuum is not powerful enough to create a counterflowing stream and instead a coflowing stream is present. The primary jet is vectored if suction is applied asymmetrically on the top or bottom of the jet.