On the effects of free-stream turbulence on axisymmetric disc wakes
On the effects of free-stream turbulence on axisymmetric disc wakes
复制标题
自由流湍流对轴对称盘尾流的影响
DOI：
--
复制
发表时间：
2012
期刊：
影响因子：
--
通讯作者：
I. Castro
中科院分区：
文献类型：
--
作者：
E. Rind;I. Castro
利用风洞实验研究了自由流湍流对圆盘后轴对称尾迹的影响。圆盘及其尾迹被引入到具有不同湍流强度和长度尺度的各种湍流流中。有人发现，自由流湍流的存在增强了身体的阻力，因此尾流动量不足，如果它是足够的强度，改变远尾流的衰减率，并防止出现自相似。外部湍流引起尾流湍流结构的显著变化。这逐渐演变为自由流湍流本身的特征，因此其特征在于弱得多的湍流（横流）传输过程和随后的剪切应力产生的主导地位，其作用是保持剪切应力和平均速度分布。
Wind tunnel experiments have been used to study the effects of free-stream turbulence on the axisymmetric wake behind a disc. The disc and its wake were introduced to various turbulent streams having various levels of turbulence intensity and length scale. It was found that the presence of free-stream turbulence enhances the body’s drag and hence wake momentum deficit, if it is of sufficient strength, changes the far wake’s decay rate and prevents the appearance of self-similarity. The external turbulence causes a significant transformation in the wake’s turbulence structure. This gradually evolves towards the character of the free-stream turbulence itself and thus is characterised by much weaker turbulence (cross-stream) transport processes and a consequent dominance of shear stress production, which acts to maintain the shear stress and mean velocity profiles.