Abstract: The study of 3D flow structures of a lateral jet interacting with the supersonic mainstream is important for the flow separation control on the surface of supersonic aircrafts and fuel mixing of scramjet engines. The flow characteristics of the lateral jet on a flat under the condition of mainstream Mach number of Ma=4.0 is simulated with large-eddy simulation method and high order TCD/WENO hybrid scheme. The numerical results show that the main wave structures are consisted of the bow shock，the separation induced shock and the barrel shock，which is similar to the corresponding experimental results. Furthermore，the results illustrate that，due to the interaction between the jet and the main flow，the flow in the separation area in front of the jet is highly transient，the vortex structures keep changing，the vortex number varies from 2 to 4 to 6，and the streamlines on the wall surface are complex. The wake sways and the vortex tube arises，which reveals its unsteady feature.

Key words: Supersonic；Lateral jet；Large eddy simulation；3D structure

摘要： 研究超声速流动与侧向射流作用下的三维流场结构对飞行器表面流体分离控制以及超燃发动机燃料混合等具有重要作用。基于大涡模拟(LES)方法和高阶TCD/WENO混合格式，对来流马赫数Ma= 4，平板上侧向射流的流场结构特性进行了数值模拟。模拟结果表明，流场内的主要波系由弓形激波、分离诱导的激波以及桶形激波组成，这与相关实验结果相符。同时，计算结果还清晰显示了射流与主流相互作用下，射流上游的分离区流动呈现高度瞬态特性，分离区内旋涡结构不断变化，数目由2个到4个再到6个不断发展，平板表面流线复杂。射流尾涡摆动，涡管上扬，呈现非定常特性。

关键词: 超声速；侧向射流；大涡模拟；三维结构