旋转圆柱绕流的PIV实验研究

发布时间：2018-05-12 14:56

  本文选题：旋转圆柱 + 转速比　； 参考：《实验流体力学》2016年01期

【摘要】：投弃式海流剖面仪(Expendable Current Profiler,XCP)周围流场是典型的旋转圆柱绕流。探头周围流场对探头的运动状态起决定性作用,这直接关系到探头的测量性能,因此有必要对旋转圆柱周围流场进行实验研究。实验在循环水槽中进行,通过PIV对雷诺数保持不变(Re=1000)、不同圆柱旋转速度比(α=0、0.5、1.0、1.5、2.0、2.5、3.0、3.5、4.0、4.5和5.0)的圆柱下游尾流场进行研究。通过选取不同旋转速度比的任一时刻的瞬态流场,来分析旋转对圆柱尾流结构的影响。为了获得流场的频率信息,对所获得流场信息进行能谱分析来获取涡旋的脱落频率,并进一步使用正交模态分解对流场进行分析,给出了流场主要拟序结构及其能量与转速比的变化趋势。发现圆柱旋转改变圆柱尾流结构,使尾迹尺度变小。在旋转速度比0≤α≤2.0时,存在明显的周期性涡旋脱落,并且涡旋脱落的频率有逐渐升高的趋势;而且当转速比2.0α≤5.0时尾迹流场的周期性减弱,涡旋脱落变得不明显,流场表现出低频、剪切层的区域特征。随着转速变大,涡旋尺度变小。在较高旋转速度比时,流场中能量被重新分布。
[Abstract]:The flow field around the cast current profiler Expendable Current Profiler XCP) is a typical flow around a rotating cylinder. The flow field around the probe plays a decisive role in the motion state of the probe, which is directly related to the measurement performance of the probe. Therefore, it is necessary to conduct an experimental study on the flow field around the rotating cylinder. The experiment was carried out in a circulating water tank. The wake flow field of the downstream cylinder was studied by means of PIV with the Reynolds number keeping constant and the rotation velocity ratio of different cylinders (伪 -0 / 0.51.0 / 1.51.51.5/ 2.5C / 2.0 ~ 3.54.0g / 4.5 and 5.0) respectively. The influence of rotation on the wake structure of a cylinder is analyzed by selecting the transient flow field at any time with different rotational velocity ratios. In order to obtain the frequency information of the flow field, the frequency of vortex shedding is obtained by energy spectrum analysis, and the flow field is analyzed by orthogonal mode decomposition. The main quasi-sequence structures of the flow field and the variation trend of the ratio of energy to rotational speed are given. It is found that the rotation of the cylinder changes the wake structure of the cylinder and makes the wake scale smaller. When the rotation velocity ratio is 0 鈮，

本文编号：1879049