Nonstationary, Three-Dimensional Aspects of Flow Around Circular Cylinder at Critical Reynolds Numbers

Abstract

thecylinder,andahot-wireprobe fixedinthenear-wakeregion.Thereal-timesignalsmeasuredshowedthatthe flow behaviors were critically affected by the presence of separation bubble, which could be seen intermittently within a limited spanwise extent on the cylinder. Further, it is noted that physical interpretations based on the time-mean measurement results could be misleading. Rather, in this study a nonstationary data analysis technique was introduced to resolve the vortex shedding frequency in the instantaneous sense. The results obtained lead to further insights into the instantaneous flow characteristics in the critical regime.