Experiment Of Spatial Evolution Established In The Wake Of Circular Cylinder Under Interference

In this paper, the spatial evolution established in the wake of circular cylinder under interference has been investigated in the low Reynolds number by two experiments like variable speed and variable distance. The shedding frequency of vortex with the form of spatial evolution of flow field in specific Reynolds number has been analyzed. And also analyzed the shedding frequency of vortex with the form of spatial evolution in the wake of two circular cylinders serial and two circular cylinders arranged perpendicular to each-other in the middle layer and the shear layer at the different spacing. At last, analyze the spatial evolution established in the wake of circular cylinder under interference with same frequency, half frequency and times frequency. Find out the law of the spatial evolution established in the wake of circular cylinder under different interference.The results are obtained that in the low Reynolds number the condition of parallel vortex can not merge. Only by the condition of tilt vortex with a bigger Reynolds number can find the vortex merged. When modal A appears, the vortex must be merged.Through contrasted the experimental results, we find out that the spatial evolution established in the wake of circular cylinder under different interference were Obvious different. On the whole, comparison with one circular cylinder, the vortex after two circular cylinders serial and two circular cylinders arranged perpendicular to each other can merge earlier and enlarge the energy. It also influenced on the different spacing. On the contrary, under the interference of same frequency, half frequency and times frequency, the spatial evolution has be inhibited and the vortex will merger delay.