尾缘修形的二元喷管内外流场数值研究

针对美国第四代战斗机F-22在二元收-扩喷管设计应用上的特点,利用时间推进的有限体积法对二元喷管尾缘修形前后非矢量状态下的内外流混合流场进行了数值模拟。结果表明:二元喷管出口尾缘修形使得喷管出口下游流场中出现了很强的流向涡,能够促进内外流的强化混合,对缩短高温核心区、加快尾喷流沿流向的温度衰减有明显效果,对抑制尾喷流的红外辐射有一定好处。 

Numerical Investigation of Two-Dimensional Nozzle with Trailing Edge Modification

The numerical simulation of three dimensional internal and external flows for non-vectoring two-dimensional nozzles with or without trailing edge modification was conducted by means of time marching finite volume method.The difference between the modified and unmodified nozzle was found.Two couple of counter-rotating streamwise strong vortices which can enhance the jet flow mixing appeared around the modified nozzle trailing edge.And these induced vortices have greater effect on temperature distribution of the exhaust plume.The result of this research shows that the design of trailing edge modification can evidently reduce the length of high temperature domain of the exhaust plume and may be benefit to the reduction of infrared radiation.