TY - JOUR
T1 - Spectral analysis of the evolution of energy-containing eddies
AU - Kannadasan, Ezhilsabareesh
AU - Atkinson, Callum
AU - Soria, Julio
N1 - Funding Information:
The authors would like to acknowledge the funding of this research by the Australian Research Council through a Discovery Grant. The authors also acknowledge the computational resources provided by the Pawsey Supercomputing Centre and the National Computational Infrastructure (NCI), through computational grants awarded by the National Computational Merit Allocation Scheme (NCMAS), funded by the Australian Government. E. K. gratefully acknowledges the support provided by a Monash Graduate Scholarship (MGS) and a Monash International Tuition Scholarship (MITS).
Publisher Copyright:
© The Author(s), 2023. Published by Cambridge University Press.
PY - 2023/1/25
Y1 - 2023/1/25
N2 - Energy-containing eddies (energy-eddies) are the elementary structures of wall turbulence that carry most of the kinetic energy and momentum. Despite the consensus that energy-eddies can self-sustain at each relevant length scale, their precise origin and spatial evolution are currently not well understood. In this study, we examine the spatial evolution of energy-eddies by quenching them at the inflow of a turbulent channel flow. Our study shows that the eddies involved in the energy cascade cannot be sustained without the energy-eddies. The streamwise velocity spectra of the evolving flow start to recover at a spanwise wavelength of, equal to the near-wall spacing of streaks in the buffer layer located at, whereas there are no active vortical motions in the streamwise vorticity spectra until the energy at the streak location is re-established. Hence, the present study demonstrates that in a spatially evolving flow, the formation of near-wall streaks is the primary process necessary in the recovery of energy-eddies.
AB - Energy-containing eddies (energy-eddies) are the elementary structures of wall turbulence that carry most of the kinetic energy and momentum. Despite the consensus that energy-eddies can self-sustain at each relevant length scale, their precise origin and spatial evolution are currently not well understood. In this study, we examine the spatial evolution of energy-eddies by quenching them at the inflow of a turbulent channel flow. Our study shows that the eddies involved in the energy cascade cannot be sustained without the energy-eddies. The streamwise velocity spectra of the evolving flow start to recover at a spanwise wavelength of, equal to the near-wall spacing of streaks in the buffer layer located at, whereas there are no active vortical motions in the streamwise vorticity spectra until the energy at the streak location is re-established. Hence, the present study demonstrates that in a spatially evolving flow, the formation of near-wall streaks is the primary process necessary in the recovery of energy-eddies.
KW - turbulence simulation
KW - turbulence theory
KW - turbulent boundary layers
UR - http://www.scopus.com/inward/record.url?scp=85146898722&partnerID=8YFLogxK
U2 - 10.1017/jfm.2022.1081
DO - 10.1017/jfm.2022.1081
M3 - Article
AN - SCOPUS:85146898722
SN - 0022-1120
VL - 955
JO - Journal of Fluid Mechanics
JF - Journal of Fluid Mechanics
M1 - R1
ER -