3-Dimensional Structure of Eddy in Free Turbulence Flow

使用带有X-探头的热线风速计阵列同时进行了一系列测量。数据显示，这些涡排由甜甜圈型大尺度涡旋及其频繁配对组成，从而产生更大的涡旋。这些涡在喷流中心线以外的相互作用，打破了甜甜圈型的大尺度涡，形成了三维的中小尺度涡。在这个过程中，流动是随机的。在远离喷嘴的区域，一些大尺度涡继续配对并形成在射流中心线两侧近似交替的对旋涡的构型。

A series of measurements was made simultaneously by using arrays of hot-wire anemometers with X-probes. The data show the rows consisted of doughnut-type large-scale vortices and their frequent pairing which results in larger vortices. The interaction of these vortices beyond the jet centrline breaks the doughnut-type large-scale vortices and forms three-dimensional medium and small-sized vortices. The flow is randomized through this process. Some large scale vortices continue to pair and form the configuration of counter-rotating vortices approximately alternating on opposite sides of the jet centerline in the region far from the nozzle.