Visualization of quantum vortex in super fluid and study of universality in turbulence based on pressure measurement

当液氦的温度低于2.17K时，它成为无粘度的超流体。在这种情况下，我们可以期望流体湍流的高雷诺数特性。在这项研究中，我们成功地开发了超流体的可视化技术，可以观察到量子涡旋的运动。此外，还研制了小型压力探头，用于精确测量压力波动。该方法应用于紊流边界层近壁面区域。利用概率密度函数的不变假设，提出了近壁区压力强度的修正方法。

When the liquid helium has its temperature below 2.17K, it becomes a super fluid with no viscosity. Under this condition, we can expect high Reynolds number property in fluid turbulence. In this study, we successfully developed the visualization technique of super fluid and can observe the quantum vortex motions. Also, the small pressure probe is developed to measure accurate pressure fluctuations. This technique is applied to the near-wall region of turbulent boundary layer. Using the invariant assumption of probability density functions, we suggest the correction method of pressure intensity near wall region.