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Download fileThe importance of non-normal contributions to velocity gradient tensor dynamics for spatially developing, inhomogeneous, turbulent flows
journal contribution
posted on 2019-11-21, 15:15 authored by P Beaumard, ORH Buxton, Chris KeylockChris KeylockWe investigate the properties of the velocity gradient tensor for spatially evolving turbulent flows (a near-wake, two axisymmetric jets and a planar mixing layer). Emphasis is placed on the study of the normal and non-normal parts of the tensor. Non-normality plays a greater role in the dynamics than is observed for HIT and does so for all spatial locations examined. This implies a greater role for viscosity or the deviatoric part of the pressure Hessian. Results for the wake flow, where we isolate the coherent part of the dynamics using a modal decomposition, clarifies how these competing
effects operate. Previous studies have shown the shape of the Q-R diagram (formed by the second and third invariants of the characteristic equation for the tensor) is approximately universal at small-scales for different flows. The non-normal dynamics are neglected in the Q-R approach but appear to differ significantly between flows.
History
School
- Architecture, Building and Civil Engineering
Published in
Journal of TurbulenceVolume
20Issue
9Pages
577 - 598Publisher
Taylor and FrancisVersion
- AM (Accepted Manuscript)
Rights holder
© Taylor and FrancisPublisher statement
This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Turbulence on 29th Oct 2019, available online: https://doi.org/10.1080/14685248.2019.1685095Acceptance date
2019-10-15Publication date
2019-10-29Copyright date
2019eISSN
1468-5248Publisher version
Language
- en