论文部分内容阅读
本文利用流动显示方法研究圆管湍流的近壁涡结构。采用激光诱导荧光技术显示流场。以每秒25帧的CCD摄象机记录近壁流动结构。通过图象时间序列计算纵向涡的平均间距和平均猝发周期。实验结果表明:圆管湍流的近壁结构和平壁湍流结构类似,但是平均间距和猝发周期均大于平壁湍流的相应参数。本文还利用图象处理技术重构近壁涡的空间图象。
In this paper, the flow display method is used to study the near-wall vortex structure of circular tube turbulence. Laser-induced fluorescence was used to visualize the flow field. CCD camera at 25 frames per second recorded near-wall flow structure. The average longitudinal vortices and the average burst period are calculated from the image time series. The experimental results show that the near-wall structure of circular tube turbulent flow is similar to that of flat-wall turbulent flow, but the average spacing and the burst period are larger than the corresponding parameters of flat-wall turbulent flow. In this paper, image processing techniques are also used to reconstruct the spatial image of vortex near the wall.