A scanning PIV method for fine-scale turbulence measurements
A scanning PIV method for fine-scale turbulence measurements
复制标题
DOI：
10.1007/s00348-014-1857-7
复制
发表时间：
2014-12-01
影响因子：
2.4
通讯作者：
Dawson, James R.
中科院分区：
文献类型：
--
作者：
Lawson, John M.;Dawson, James R.
提出了一种将扫描PIV和层析重建相结合的混合技术，对湍流中的细尺度运动进行空间和时间分辨测量。这项技术使用一个或两个高速摄像机来记录激光薄片在测量体积上快速遍历时的粒子图像。这与粒子场的层析重建的快速方法相结合，以便与PIV互相关一起使用。该方法在一个大型混合罐中进行了数值测试，该混合罐在R-lambda等于或等于219处产生了轴对称均匀湍流。参数调查确定了扫描PIV设置的重要参数，并为感兴趣的实验者提供了获得最佳精度的指导。报告了最佳的板材间距和厚度，并发现在相当低的扫描速度下可以获得准确的结果。双摄像机方法是对噪声最稳健的方法，允许精确测量速度梯度并直接确定耗散率。
A hybrid technique is presented that combines scanning PIV with tomographic reconstruction to make spatially and temporally resolved measurements of the fine-scale motions in turbulent flows. The technique uses one or two high-speed cameras to record particle images as a laser sheet is rapidly traversed across a measurement volume. This is combined with a fast method for tomographic reconstruction of the particle field for use in conjunction with PIV cross-correlation. The method was tested numerically using DNS data and with experiments in a large mixing tank that produces axisymmetric homogeneous turbulence at R-lambda similar or equal to 219. A parametric investigation identifies the important parameters for a scanning PIV setup and provides guidance to the interested experimentalist in achieving the best accuracy. Optimal sheet spacings and thicknesses are reported, and it was found that accurate results could be obtained at quite low scanning speeds. The two-camera method is the most robust to noise, permitting accurate measurements of the velocity gradients and direct determination of the dissipation rate.