This study investigated the effect of large-scale structures including large-scale motions (LSMs) and hairpin vortex in the log-region on the bursting phenomenon in the buffer layer using the simultaneous measurement of the streamwise velocity fluctuation in the log-region and buffer layer of the turbulent boundary layer (TBL) with a multi-channel hot-wire probe. The Reynolds number in the present study, calculated from the friction velocity $u_{\tau }$, was ${\mathit{Re}}_{\tau }=\delta u_{\tau }/\nu =1260$, where $\delta$ is the boundary layer thickness and $\nu$ is the kinematic viscosity. The LSMs were classified as positive large-scale motions (pLSMs) and negative large-scale motions (nLSMs) based on their streamwise velocities. Their effect on the bursting that was detected by the Variable-Interval Time-Averaging (VITA) technique was visualized. As a result, it was evident that the bursting became active with the existence of the pLSMs, while it was suppressed with the nLSMs. In addition, hairpin vortex was observed by applying the VITA technique to the velocity fluctuation of the log-region. Further investigation revealed that the hairpin vortex can also be observed in the log-region with the condition that the bursting was detected in the buffer layer, suggesting that the existence of a hairpin vortex in the log-region slightly increased the bursting phenomenon near the wall.

本研究通过同时测量对数区和缓冲区中的流向速度波动，研究了包括对数区中的大规模运动（LSM）和发夹涡在内的大规模结构对缓冲层爆裂现象的影响。带有多通道热线探针的湍流边界层（TBL）层。根据摩擦速度计算出的本研究中的雷诺数${ü}_{\tau }$， 曾是 ${\mathit{关于}}_{\tau }=\delta {ü}_{\tau }/\nu =1260$， 在哪里 $\delta$ 是边界层的厚度， $\nu$是运动粘度。根据它们的流速度，将LSM分为正向大规模运动（pLSMs）和负向大规模运动（nLSMs）。可视化了它们对通过可变间隔时间平均（VITA）技术检测到的突发的影响。结果，明显的是，爆裂随着pLSM的存在而变得活跃，而被nLSM抑制了。此外，通过将VITA技术应用于对数区域的速度波动，可以观察到发夹涡。进一步研究表明，在缓冲层中检测到爆裂的条件下，也可以在对数区域中观察到发夹涡，这表明在对数区域中存在发夹涡会稍微增加壁附近的爆裂现象。 。