Turbulence characteristics inside a turbulent spot in plane Poiseuille flowTurbulence characteristics inside a turbulent spot in plane Poiseuille flow are investigated by analyzing a database obtained from a direct simulation. The spot area is divided into two distinct regions - a turbulent area and a wave area. It is found that the flow structures inside the turbulent area have strong resemblance to those found in the fully-developed turbulent channel flow. A suitably defined mean and rms fluctuations as well as the internal shear-layer structures are found to be similar to the turbulent counterpart. In the wave area the inflexional mean spanwise profiles cause a rapid growth of oblique waves, which break down to turbulence. The rms fluctuations and Reynolds stress are found to be higher in that area, and the shear-layer structures are similar to those observed in the secondary instability of two-dimensional Tollmien-Schlichting waves.
Document ID
19900048127
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Henningson, Dan S. (MIT Cambridge, MA, United States)
Kim, John (NASA Ames Research Center Moffett Field, CA, United States)