数字全息粒子图像测速技术应用于旋转流场测量的研究

Digital Holography Particle Image Velocimetry Applied for Measurement of the Rotating Flow Fields

将数字全息粒子图像测速(DHPIV)技术应用于旋转流场的三维空间速度测量当中。提出了一种新的焦平面定位方法,即综合灰度梯度法,对数字全息中粒子的焦平面进行精确定位,获得了粒子的空间坐标。针对数字全息粒子图像测速技术中的粒子匹配问题,采取三维互相关算法对流场中的示踪粒子进行空间匹配。将基于综合灰度梯度法和三维互相关算法的数字粒子图像测速技术运用到旋转流场全息图中,获得了局部的三维可视化速度场,与理论模型吻合很好。结果表明,该技术能够很好地应用于旋转流场的测量研究当中。

To accurately obtain the three-dimension（3D） velocities fields of the rotating flow fields,digital holography particle image velocimetry（DHPIV） is presented.A new method,namely the integrated gray-level gradient,is used to locate the focal plane of the particle and to extract the 3D particle′s coordinate.The 3D cross-correlation pairing algorithm is applied for the pairing of particles.The rotating flow fields′ 3D visual velocities fields,corresponded to the theoretical modeling,are obtained by DHPIV based on the integrated gray-level gradient method and the three-dimension cross-correlation pairing algorithm.The experimental results demonstrate that this technology can be applied for measurement of the rotating flow fields effectively.