超音尾喷流红外抑制方案的研究

超音速发动机尾喷流的红外抑制是超音速飞行器隐身性能的重要组成部分。本文提出两种超音速尾喷流的红外抑制方案二次旋流方案与组合波瓣方案 ,并对两种方案共 7组试验件在不同的结构和二次流速度情况下进行了大量重复试验。在旋流方案试验中 ,对二次流加旋诱发大尺度流向涡进行了系统的研究 ,得到旋流角度、二次流速度等对掺混效果的影响规律 ,试验结果表明 :对于本结构方案 ,当二次流速度为 49m/s,旋流角在 3 0°左右 ,掺混效果最好 ,且随二次流流速的增加而加强。在组合波瓣方案的试验中 ,对组合波瓣用于超音尾喷流红外抑制进行了研究 ,试验结果表明可对超音尾喷流的红外起到有效的抑制作用。

Experimental Investigation of Exhaust Jet Infrared Suppression for Supersonic Flow

The supersonic exhaust jet infrared suppression is one of the most important components of the supersonic aircraft performance.The projects of the second swirl flow and the combined petal lobe are provided in this paper.Their mechanism is that mixer ejector can cause large scale streamwise vortices into the downstream.It is these vortices that intake much more amount of atmosphere which also can stir up the main flow.The mixing zone between plume and external flow increases and the length of the central core zone of turbulent flow becomes shorter,so the infrared radiation of the jet exhaust decreases.The swirl ejector is used in the first project.The experimental results show that the higher is the speed of external swirl flow,the better is the performance of stir.The experimental results also show that when the angle of swirl flow is about 30 degrees,the performance is the best for the project.The combined petal lobe is used in the second project.The experimental results show that it is practicable to use combined petal lobe for the infrared suppression of supersonic flow.