Flow inside the axial test turbine VT-400 is measured by using a standard methodology of Particle Image Velocimetry (PIV). The studied area lies between the stator and rotor wheel in meridional plane. This area covers both: the regular flow near hub and the endwall secondary structures as well. Regular structure of wakes and jets past stator blades is observed in terms of mean velocities and turbulence intensity. The fluctuations are close to isotropy and the energy distribution across length-scales exhibits almost Kolmogorov scaling. Near the hub, we observe secondary vortices. Despite the positive radial ejections in that regions, these secondary vortices drift towards the hub, they dissipate energy and circulation and their core grows in size.

轴向测试涡轮机 VT-400 内部的流动是通过使用粒子图像测速 (PIV) 标准方法来测量的。研究区域位于子午面内的定子轮和转子轮之间。该区域涵盖：轮毂附近的常规流动和端壁二级结构。根据平均速度和湍流强度观察经过定子叶片的尾流和射流的规则结构。波动接近各向同性，并且跨长度尺度的能量分布几乎呈现柯尔莫哥洛夫缩放。在中心附近，我们观察到次级涡流。尽管这些区域存在正径向喷射，但这些次级涡流会向中心漂移，它们会耗散能量和循环，并且其核心尺寸会增大。