On the Difficulties in Resolving the Viscous Sublayer in Wall-Bounded Turbulence
On the Difficulties in Resolving the Viscous Sublayer in Wall-Bounded Turbulence
复制标题
论壁面湍流中粘性子层的求解难题
DOI：
10.1007/978-1-4020-2313-2_14
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
K. Beronov
中科院分区：
文献类型：
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作者：
F. Durst;K. Beronov
通过对平面槽道湍流DNS中近壁区+< 10的湍流速度单点统计数据与壁面湍流实验中相应数据的比较，发现DNS数据存在对湍流强度和湍流度预测过高的问题。这是对数型伪非解析性的结果，它是由于数值近似违反了壁面法向速度分量v的方程中高阶项iny+的精细抵消。由此产生的非解析附加误差传播到所有的流体动力场，但影响最强烈的vwhich消失在壁比其他速度分量。它的归一化矩如平坦度因子Fv由误差控制，具有显著的影响。例如，在具有更高分辨率的DNS中，Fvis的过度预测更大。这个矛盾的观察解释了一个简单的模型占高的折射率和对数误差的vnear壁。
Comparison of one-point statistics of turbulent velocities in the near-wall regiony+< 10 from DNS of turbulent plane channel flows with corresponding data from experiments on wall-bounded turbulence show that DNS data are plagued by an overprediction of turbulent intensity and intermittency. This is the result of a spurious non-analyticity of logarithmic type, which arises from the violation by numerical approximations of a fine cancellation of high-order terms iny+in the equation for the wall-normal velocity componentv. The arising non-analytic additive error propagates into all hydrodynamic fields, but affects most stronglyvwhich vanishes at the wall faster than the other velocity components. Its normalized moments like the flatness factorFvare dominated by the error, with dramatic effects. For example, overprediction ofFvis larger in DNS with higher resolution. This paradoxical observation is explained by a simple model accounting for the high intermittency and for the log-errors ofvnear the wall.