Visualization of turbulence in flow about a bluff bodyA visual diagnostic investigation of turbulence in flow about a circular cylinder was conducted in order to gain a physical insight into the model for the structure of turbulence in flow around a bluff body advanced by the vorticity-amplification theory. A frame-by-frame qualitative and quantitative examination of selected movie strips over time intervals up to more than 800 ms was performed. The selective stretching of cross-vortex tubes, their streamwise tilting, the emergence of an organized turbulent flow pattern near the stagnation zone and the growth of a turbulent boundary layer were clearly revealed by the visualization. In particular, the visualization indicated that the cross-vortex tubes conveyed by the diverging stagnation flow constitute a coherent substructure within the overall turbulent flow that is triggered to its fullest manifestation by the stretching mechanism.
Document ID
19800048662
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Sadeh, W. Z. (Colorado State Univ. Fort Collins, CO, United States)
Brauer, H. J. (Colorado State University Fort Collins, Colo., United States)