Kriete D M, McKee G R, Fonck R J, Smith D R, Whelan G G, Yan Z
Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Rev Sci Instrum. 2018 Oct;89(10):10E107. doi: 10.1063/1.5036535.
The 2D turbulent × flow-field is inferred from density fluctuation images obtained with the beam emission spectroscopy diagnostic on DIII-D using the orthogonal dynamic programming velocimetry algorithm. A synthetic turbulence model is used to test the algorithm and optimize it for measuring zonal flows. Zonal flow measurements are found to require a signal-to-noise ratio above ∼10 and a zonal flow wavelength longer than ∼2 cm. Comparison between the velocimetry-estimated flow-field and the × flow-field using a nonlinear gyrokinetic GENE simulation finds that the flow-fields have identical spatial structure and differ only by the mean turbulence phase velocity, which is spatially uniform in this flux tube simulation.
二维湍流×流场是通过使用正交动态规划测速算法，从在DIII-D上采用束发射光谱诊断获得的密度涨落图像中推断出来的。使用一个合成湍流模型来测试该算法，并对其进行优化以测量带状流。发现带状流测量需要信噪比高于约10，且带状流波长大于约2厘米。使用非线性陀螺动力学GENE模拟对测速估计的流场和×流场进行比较，结果发现流场具有相同的空间结构，仅在平均湍流相速度上有所不同，在该通量管模拟中平均湍流相速度在空间上是均匀的。
