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对槽道内涡波流场采用二维粒子图像测速仪(2DPIV)进行了实验研究,利用POD技术对获取的2DPIV瞬态速度矢量场进行了主导模态重构,利用POD重构流场得到了槽道内的平均流速和湍流动能分布;采用大涡PIV方法对湍流动能耗散率分布进行了计算。结果表明重构流场表征了原始流场的主导结构,剔除了噪声等干扰信息;大涡PIV方法能有效地估算动能耗散率的分布;湍流动能在壁面附近较小,在接近槽道中心区域湍流动能越来越大,呈现出射流的特征;动能耗散率的峰值出现在壁面附近和槽道中心区域,动能耗散率随着远离壁面程度的增加先降低后逐渐增加直至达到峰值。
Two-dimensional particle image velocimetry (2DPIV) was used to study the vortex flow field in the channel. The POD technique was used to conduct the dominant mode reconstruction of the 2DPIV transient velocity vector field. The POD reconstruction flow field was used The average velocity and the distribution of turbulent kinetic energy in the channel, and the large-eddy PIV method was used to calculate the distribution of turbulent kinetic energy dissipation rate. The results show that the reconstructed flow field characterizes the dominant structure of the original flow field and removes the noise and other disturbance information. The large-eddy PIV method can effectively estimate the distribution of kinetic energy dissipation rate. The turbulent kinetic energy is small near the wall surface. The regional turbulent kinetic energy is larger and larger, showing the characteristics of jet. The peak of kinetic energy dissipation rate appears in the vicinity of the wall and in the center of the channel. The kinetic energy dissipation rate decreases first and then increases to the peak value as the distance from the wall increases.