A circulant-matrix-based hybrid optical flow method for PIV measurement with large displacement
A circulant-matrix-based hybrid optical flow method for PIV measurement with large displacement
复制标题
基于循环矩阵的大位移PIV测量混合光流方法
DOI：
10.1007/s00348-021-03317-1
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发表时间：
2021-10
影响因子：
2.4
通讯作者：
Zhouping Yin
中科院分区：
文献类型：
--
作者：
Zhenxing Ouyang;Hua Yang;YongAn Huang;Zhang Qinghu;Zhouping Yin
对于具有大速度梯度和高速度范围的流体流动，如涡流和射流，其精确测量仍然是流体动力学研究中最重要和具有挑战性的。粒子图像测速（PIV）是一种用于确定流体速度的成熟实验技术;然而，当示踪粒子的位移远大于其尺寸时，它无法获得准确的结果（Liu in J Fluids Eng 142（5）：054051，2020）。在这项研究中，我们提出了一种新的混合光流公式，包括两个部分，即基于循环矩阵的相关性和自适应权重光流，来解决这个问题。首先，提出了一种基于循环矩阵的相关方法，对询问窗口进行循环采样，以提高速度测量范围和测量精度。随后，我们设计了一个特定的光流，其正则化参数可以随速度梯度的变化而调整，并引入了非二次罚函数以实现更好的稳定性和收敛性。由基于循环矩阵的相关性提供的解决方案被用作初始化，以考虑具有小颗粒的大位移，并在真实的时间内校正以下自适应权重光流，以准确地捕获小涡旋和湍流结构。速度场的估计超过合成和实验粒子图像，并与先进的PIV方法的速度结果进行了比较。结果表明，该方法在测量大速度梯度和高速度范围的流体流动时，能够成功地捕捉到小尺度涡和湍流结构。
The accurate measurement of fluid flows with large velocity gradients and a high velocity range, such as vortex flow and jet flow, is still paramount and challenging in fluid dynamics research. Particle image velocimetry (PIV) is a well-established experimental technique for determining fluid velocities; however, it cannot obtain an accurate result when the displacements of tracer particles are much larger than their sizes (Liu in J Fluids Eng 142(5):054051, 2020). In this study, we propose a novel hybrid optical flow formulation that consists of two parts, namely a circulant-matrix-based correlation and an adaptive weight optical flow, to solve this problem. First, a novel correlation method based on a circulant matrix is proposed, where the interrogation window is cyclically sampled to improve the measurable velocity range and measurement accuracy. Subsequently, we design a specific optical flow whose regularization parameters can be adjusted with changes in the velocity gradient and introduce a non-quadratic penalty function to achieve better stability and convergence. The solution provided by the circulant-matrix-based correlation is used as an initialization to account for large displacements with small particles and corrects the following adaptive weight optical flow in real time to accurately capture small vortex and turbulent structures. Velocity fields are estimated over synthetic and experimental particle images, and the velocity results are compared with advanced PIV methods. The results and comparisons show that the proposed method successfully achieves good performance in capturing small-scale vortices and turbulent structures when measuring fluid flows with large velocity gradients and a high velocity range.
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影响因子：
2.4
作者：
R. Theunissen;F. Scarano;M. Riethmuller
通讯作者：
R. Theunissen;F. Scarano;M. Riethmuller
影响因子：
2.4
作者：
Paul Ruhnau;Timo Kohlberger;C. Schnörr;H. Nobach
通讯作者：
Paul Ruhnau;Timo Kohlberger;C. Schnörr;H. Nobach
DOI：
10.1007/978-3-642-83787-6_4
发表时间：
1989
期刊：
--
影响因子：
--
作者：
L. Lourenço
通讯作者：
L. Lourenço
粒子图像测速中的新型自适应采样方法
影响因子：
2.4
作者：
Yu, Kaikai;Xu, Jinglei;Tang, Lan;Mo, Jianwei
通讯作者：
Mo, Jianwei
影响因子：
2
作者：
Tianshu Liu;D. Salazar;Hassan Fagehi;H. Ghazwani;J. Montefort;P. Merati
通讯作者：
Tianshu Liu;D. Salazar;Hassan Fagehi;H. Ghazwani;J. Montefort;P. Merati