壁界湍流的热线风速测量法和油膜干涉测量法测量中不确定度的评定
Assessment of uncertainties in hot-wire anemometry and oil-film interferometry measurements for wall-bounded turbulent flows
摘要：
在这项研究中，热线风速（HWA）和油膜干涉（OFI）测量的不确定度的来源进行了评估。统计和经典的方法都用于正向和反向问题，使测量量的整体不确定度的贡献可以进行评估。参数之间的相关性通过具有变量误差（EiV）模型的贝叶斯推断来考虑。在正问题中，发现非常小的差异时，使用蒙特卡罗（MC），多项式混沌展开（PCE）和线性扰动方法。在用HWA测量流速时，结果表明，当考虑参数之间的相关性时，估计的不确定度比不考虑参数之间的相关性时低。此外，与Sobol指数的全球敏感性分析表明，HWA测量是最敏感的线电压，在OFI的情况下，最敏感的因素是计算的条纹速度。壁面切应力、摩擦速度和粘性长度的相对误差分别为0.44%、0.23%和0.22%。请注意，这些值低于其他壁边界湍流研究中报告的值。注意，在大多数壁面湍流的研究中，参数之间的相关性没有被考虑，在确定测量量的总体不确定度时，直接将各个参数的不确定度相加。在目前的分析中，我们考虑到这些相关性，这可能会导致一个较低的整体不确定性估计，由于误差消除。此外，我们的研究结果还表明，获得准确的内标度速度测量的关键方面是风洞流的质量，这是更关键的壁面剪应力测量的准确性。
英文摘要：
In this study, the sources of uncertainty of hot-wire anemometry (HWA) and oil-film interferometry (OFI) measurements are assessed. Both statistical and classical methods are used for the forward and inverse problems, so that the contributions to the overall uncertainty of the measured quantities can be evaluated. The correlations between the parameters are taken into account through the Bayesian inference with error-in-variable (EiV) model. In the forward problem, very small differences were found when using Monte Carlo (MC), Polynomial Chaos Expansion (PCE) and linear perturbation methods. In flow velocity measurements with HWA, the results indicate that the estimated uncertainty is lower when the correlations among parameters are considered, than when they are not taken into account. Moreover, global sensitivity analyses with Sobol indices showed that the HWA measurements are most sensitive to the wire voltage, and in the case of OFI the most sensitive factor is the calculation of fringe velocity. The relative errors in wall-shear stress, friction velocity and viscous length are 0.44%, 0.23% and 0.22%, respectively. Note that these values are lower than the ones reported in other wall-bounded turbulence studies. Note that in most studies of wall-bounded turbulence the correlations among parameters are not considered, and the uncertainties from the various parameters are directly added when determining the overall uncertainty of the measured quantity. In the present analysis we account for these correlations, which may lead to a lower overall uncertainty estimate due to error cancellation. Furthermore, our results also indicate that the crucial aspect when obtaining accurate inner-scaled velocity measurements is the wind-tunnel flow quality, which is more critical than the accuracy in wall-shear stress measurements.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
