High-spatial-resolution (HSR) two-component, two-dimensional particle-image-velocimetry (2C-2D PIV) measurements of a zero-pressure-gradient (ZPG) turbulent boundary layer (TBL) and an adverse-pressure-gradient (APG)-TBL were taken in the Laboratoire de Mécanique des Fluides de Lille (LMFL) High Reynolds number Boundary Layer Wind Tunnel. The ZPG-TBL has a momentum-thickness based Reynolds number $R{e}_{{\delta }_2}={\delta }_2{U}_e∕\nu =7,750$ (where ${\delta }_2$ is the momentum thickness and $U_e$ is the edge velocity), while the APG-TBL has a $R{e}_{{\delta }_2}=16,240$ and a Clauser’s pressure gradient parameter $\beta ={\delta }_1{P}_x∕{\tau }_w=2.27$ (where ${\delta }_1$ is the displacement thickness, $P_x$ is the pressure gradient in streamwise direction and ${\tau }_w$ is the wall shear stress). The 2C fluctuating flow field of each TBL was decomposed using proper orthogonal decomposition (POD) to investigate the large-scale motions (LSMs). The LSMs are found to be energized in the outer-layer, becoming stronger in the presence of the adverse-pressure-gradient. Profiles of the conditionally averaged Reynolds stresses show that high-momentum LSMs contribute more to the Reynolds stresses than low-momentum LSMs from the wall to the end of the log-layer while the opposite is found in the wake region. The cross-over point between the profiles of the conditionally averaged Reynolds stresses from the high- and low-momentum LSMs always has a higher value than the corresponding Reynolds stress from the unconditional ensemble average at the same wall-normal location. This difference is up to 80% in the Reynolds streamwise and shear stresses and up to 15% in the Reynolds wall-normal stresses. Furthermore, the cross-over point in the APG-TBL is found to be further from the wall than in the ZPG-TBL. The conditional Reynolds streamwise and shear stresses without the LSMs are reduced by up to 42% in the ZPG-TBL and by up to 50% in the APG-TBL, while having a minimal effect on the conditional Reynolds wall-normal stress without the LSMs in both the ZPG- and APG-TBL.

零压力梯度 (ZPG) 湍流边界层 (TBL) 和逆压力梯度的高空间分辨率 (HSR) 二分量、二维粒子图像测速 (2C-2D PIV) 测量(APG)-TBL 取自里尔流体力学实验室 (LMFL) 高雷诺数边界层风洞。ZPG-TBL 具有基于动量厚度的雷诺数$\mathrm{电阻}{\mathrm{电子}}_{{\delta }_2}={\delta }_2{你}_{\mathrm{电子}}∕\nu =7,750$ （在哪里 ${\delta }_2$ 是动量厚度和 ${你}_{\mathrm{电子}}$ 是边缘速度），而 APG-TBL 有 $\mathrm{电阻}{\mathrm{电子}}_{{\delta }_2}=16,240$ 和克劳瑟压力梯度参数 $\beta ={\delta }_1{磷}_X∕{\tau }_{瓦}=2.27$ （在哪里 ${\delta }_1$ 是位移厚度， ${磷}_X$ 是流向的压力梯度和 ${\tau }_{瓦}$是壁面剪应力）。使用适当的正交分解 (POD) 分解每个 TBL 的 2C 波动流场，以研究大规模运动 (LSM)。发现 LSM 在外层被激发，在逆压力梯度的存在下变得更强。条件平均雷诺应力的剖面图表明，从壁到测井层末端，高动量 LSM 对雷诺应力的贡献大于低动量 LSM，而在尾流区域则相反。来自高动量和低动量 LSM 的条件平均雷诺应力的轮廓之间的交叉点总是比来自相同壁法线位置的无条件集合平均值的相应雷诺应力具有更高的值。这种差异在雷诺流向和剪切应力中高达 80%，在雷诺壁法向应力中高达 15%。此外，发现 APG-TBL 中的交叉点比 ZPG-TBL 中的交叉点离壁更远。在没有 LSM 的情况下，条件雷诺流向和剪切应力在 ZPG-TBL 中降低了 42%，在 APG-TBL 中降低了 50%，同时对没有 LSM 的条件雷诺壁法向应力的影响最小在 ZPG- 和 APG-TBL 中。