摘要
采用高时间分辨率粒子图像测速技术(TRPIV)在水槽中对不同雷诺数下的波形壁面湍流空间流场进行测量,得到瞬时湍流边界层速度场空间分布的时间序列,分析了雷诺应力分量和平均速度变形率分量的空间分布,发现其在近壁区受波形壁面影响比较大,周期性比较明显,而远离壁面时受壁面条件的影响较小。利用空间互相关技术分析了雷诺应力分量与平均速度变形率分量之间的流向相位关系,发现二者在流向空间上存在相位差,且相位差的分布由壁面向外区从0先逐渐减小,在0.4—0.5波形壁波长的法向位置处达到最小值,然后再逐渐增大,且在一定的范围内雷诺数的变化对相位差的影响并不大。验证了湍流雷诺应力复涡黏性模型的合理性,为建立更加准确预测非平衡湍流的复涡黏性模型提供了实验依据。
The time series of velocity vector field in the turbulent boundary layer over a wavy wall were measured by using time-resolved particle image velocimetry （TRPIV） at three different Reynolds numbers in a water channel, and the spatial distributions of Reynolds stress component and mean velocity strain rate component were obtained by ensemble average. The closer distance to the wall, the bigger values of the components and the more obvious periodicity the same as the wavy wall. The spatial phase relationships between mean velocity strain rate components and Reynolds stress components in streamwise direction were investigated by using the spatial cross-correlation technique. The spatial phase differences between Reynolds stress components and mean velocity strain rate components appeared, and they increased gradually after decreasing from zero away from the wavy wall in wall- normal direction. At 0.4-0.5 times the wavelength of wavy wall, the phase differences reached the minimum, and the effect of the Reynolds number on the phase differences was very small in a certain range. The reasonability of the complex eddy viscosity model was confirmed by these experimental evidences, which helps to build a complex eddy viscosity model to forecast non-equilibrium turbulence more accurately.
出处
《化学工程》
CAS
CSCD
北大核心
2013年第11期38-42,共5页
Chemical Engineering(China)
基金
国家自然科学基金资助项目(11272233)
国家重点基础研究发展计划资助项目(2012CB720101)
中国科学院力学研究所非线性力学国家重点实验室对外开放基金资助项目
关键词
波形壁面
湍流
互相关技术
相位差
复涡黏模型
wavy wall
turbulence
cross-correlation technique
phase difference
complex eddy viscosity model
