Abstract The assumptions that form the basis for Reynolds stress closure models have been formulated by considering canonical flows. As a result, the accuracy of Reynolds-averaged Navier–Stokes simulations can deteriorate significantly when modeling complex flows, and engineering applications would benefit from methods that can quantify the corresponding uncertainty in the predictions. This paper analyzes the performance of a previously proposed turbulence model uncertainty quantification (UQ) framework for simulations of flow through a pin-fin array. The method is a physics-based, data-free, interval approach that perturbs the Reynolds stress tensor shape towards the three limiting realizable states of anisotropy. The performance of the method is evaluated by determining whether large-eddy simulation results for the quantities of interest are encompassed by the intervals predicted by the UQ method. The results demonstrate that perturbing the stress shapes towards the one-component or two-component limit generally enhances the momentum transport between the bulk flow and wake regions, whereas perturbations towards the three-component limit suppress this transport. For quantities of interest that depend on the mean velocity and pressure field this results in predictions for uncertainty intervals that encompass the reference solution. For the turbulence kinetic energy the method fails to predict an adequate upper bound in regions with larger-scale turbulent structures, and it predicts overly conservative bounds in the pin stagnation regions. Based on these results several suggestions for improving the framework are made.

中文翻译：

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在针鳍阵列的雷诺平均 Navier-Stokes 模拟中量化湍流模型的不确定性。第 1 部分：流场

摘要 构成雷诺应力闭合模型基础的假设已通过考虑典型流而制定。因此，在对复杂流动进行建模时，雷诺平均 Navier-Stokes 模拟的准确性会显着下降，而工程应用将受益于可以量化预测中相应不确定性的方法。本文分析了先前提出的湍流模型不确定性量化 (UQ) 框架的性能，用于模拟通过针鳍阵列的流动。该方法是一种基于物理学的、无数据的间隔方法，可将雷诺应力张量形状扰动到各向异性的三个极限可实现状态。通过确定 UQ 方法预测的区间是否包含感兴趣量的大涡模拟结果来评估该方法的性能。结果表明，向单分量或双分量限制扰动应力形状通常会增强体流和尾流区域之间的动量传输，而向三分量限制的扰动抑制这种传输。对于取决于平均速度和压力场的感兴趣量，这会导致对包含参考解的不确定区间的预测。对于湍流动能，该方法无法在具有较大尺度湍流结构的区域中预测足够的上限，并且它在针滞留区域中预测了过于保守的边界。