论文部分内容阅读
采用大涡模拟方法数值模拟了流向和展向椭圆喷嘴的湍流横向射流,重点研究了其中旋涡结构的产生、发展等动力学演化过程.结果表明文献中所报道的横向射流基本涡结构,如反向旋转涡对、前缘涡、后缘涡、悬涡、肾涡、反肾涡等等是分别对应于新发现的横向射流中的基本涡结构——起始于喷嘴的三维拉伸涡环的局部结构,因此,在湍流横向射流中真正占主导作用的是拉伸、扭曲、沿展向摆动和沿流向扭动的三维涡环.研究还发现:涡环的脱落频率比流场信号分析得到的脉动频率小得多.
The large-eddy simulation method is used to simulate the transverse flow of turbulent flow in the direction of the elliptical nozzle and its development. The dynamic evolution process of the vortex structure is mainly studied. The results show that the basic vortex structure of transverse jet reported in the literature, To the vortex, vortex, vortex, vortices, vortex, anti-renal vortex, etc. are corresponding to the newly discovered horizontal jet in the basic structure of the vortex - starting from the nozzle of the three-dimensional drawing vortex ring Therefore, the three-dimensional vortex ring that is dominant in the turbulent lateral jet is tensile, distorted, wedged along the span and twisting along the flow direction.The study also found that the shedding frequency of the vortex ring is higher than the flow field signal analysis The resulting pulsation frequency is much smaller.