论文标题
振荡管流中的相不对称
On phase asymmetries in oscillatory pipe flow
论文作者
论文摘要
我们介绍了振荡管流的直接数值模拟（DNS）在几个无量纲的频率下的直接数值模拟（DNS）WO = {6.5、13、26}和一个固定的剪切剪切reynolds编号re_τ= 1440。从完全开发的旋转速度领域开始，该旋转速度在re_τ中，振动性流动或强度均可构成趋势或强度均匀的趋势或驱动式的繁殖。通过证明了我们的DNS结果与实验数据和文献分析预测的极好的一致性来验证数值方法，以实验数据和分析预测，以限制非振荡但湍流且振荡但层流但层流管流的限制案例。对于振荡的湍流流量，我们进一步发现了对实验中观察到的特征流特征的定性描述和我们的DNS的定性描述之间的一致性。在这里，我们专注于观察WO = 6.5时振荡性管流的正和半伴侣之间的强烈不对称行为。
We present results from direct numerical simulations (DNS) of oscillatory pipe flow at several dimensionless frequencies Wo = {6.5, 13, 26} and one fixed shear Reynolds number Re_τ = 1440. Starting from a fully-developed turbulent velocity field at that Re_τ, the oscillatory flow either relaminarises or reaches a conditionally turbulent or strongly asymmetric state depending on Wo. The numerical method is validated by demonstrating excellent agreement of our DNS results with experimental data and analytical predictions from literature for the limiting cases of non-oscillating but turbulent and oscillating but laminar pipe flow. For an oscillating turbulent pipe flow we further found a very good agreement between qualitative descriptions of the characteristic flow features observed in experiments and our DNS. Here, we focus on the observation of a strongly asymmetric behaviour between the positive and the negative half-cycles of the oscillatory pipe flow at Wo=6.5.
