Fluidic thrust vectoring for low observable aircraft
Fluidic thrust vectoring for low observable aircraft
复制标题
低可观测飞机的流体推力矢量
DOI：
--
复制
发表时间：
2002
期刊：
影响因子：
--
通讯作者：
W. Crowther
中科院分区：
文献类型：
--
作者：
M. S. Mason;W. Crowther
本文介绍了一种用于亚音速低能观测无人机的同流射流推力矢量系统的研制工作。为了研究各种几何变量对推力矢量化效果的影响，设计并建造了两个约1/10比例的射流推力矢量化试验台。这些参数包括次生间隙高度dh和科安达表面直径∅。使用六分量开销天平获得负载测量结果。推力矢量力Fz，Tv是利用非矢量主喷流的推力Fx得到推力矢量系数Cz的无量纲化。试验的质量流量比范围为0�m S/mp<；0.13，对应的动量流量比范围为0�ms/MP<；0.4。还对二维流进行了计算研究，主要是为了辅助实验演示台架的设计，并利用烟流可视化技术进一步研究了非矢量化和矢量化主射流的流动特性。研究表明，实验和计算结果都遵循相似的趋势线。在低质量流量比下会出现无法控制的“死区”。然后是一个控制区，在该控制区中可以实现连续的推力矢量控制，接着是一个假设的饱和区。二次喷吹速度、科安达表面直径和一次喷嘴与二次喷嘴高度之比决定了能否实现高效的射流推力矢量。命名一次射流m_2的横截面积为二次射流m_2的横截面积
The work presented in this paper deals with the development of a coflow fluidic thrust vectoring system for use on a low observable unmanned air vehicle operating in the subsonic flight regime. Two approximately 1/10 th scale fluidic thrust vectoring demonstrator rigs were designed and built in order to investigate the effect of various geometric variables on thrust vectoring effectiveness. These included secondary gap height, dh, and Coanda surface diameter, ∅. Load measurements were obtained using a six component overhead balance. The thrust vector force, Fz,tv, was made non-dimensional using the thrust force of the nonvectored primary jet, F x , to give a thrust vector coefficient, Cz. Tests were carried out over the mass flow ratio range 0 � m s /m p < 0.13 which corresponded to a momentum flow ratio range of 0 � Ms/Mp < 0.4. A computational investigation for 2D flow was also undertaken primarily to aid in the design of the experimental demonstrator rigs and smoke flow visualisation techniques were used to further investigate the flow characteristics of a non-vectored and a vectored primary jet. The investigation shows that both the experimental and computational results obtained follow a similar trend line. A ‘dead zone’ appears at low mass flow ratios in which no control can be achieved. There then follows a control region in which continuous thrust vector control can be achieved followed by a hypothetical saturation region. The secondary jet blowing rate, the Coanda surface diameter and the primary nozzle to secondary nozzle height ratio are seen to determine whether effective and efficient fluidic thrust vectoring can be achieved. Nomenclature Ap Cross sectional area of primary jet m 2 As Cross sectional area of secondary jet m 2