Vis enkel innførsel

dc.contributor.authorAksamit, Nikolas Olson
dc.contributor.authorHaller, George
dc.date.accessioned2023-03-30T05:17:42Z
dc.date.available2023-03-30T05:17:42Z
dc.date.issued2022-04-28
dc.description.abstractWe use the recent frame-indifferent theory of diffusive momentum transport to identify internal barriers in wall-bounded turbulence. Formed by the invariant manifolds of the Laplacian of the velocity field, the barriers block the viscous part of the instantaneous momentum flux in the flow. We employ the level sets of single-trajectory Lagrangian diagnostic tools, the trajectory rotation average and trajectory stretching exponent, to approximate both vortical and internal wall-parallel momentum transport barrier (MTB) interfaces. These interfaces provide frame-indifferent alternatives to classic velocity-gradient-based vortices and high-shear boundaries between uniform momentum zones (UMZs). Indeed, we find that these elliptic manifold approximations and MTBs outperform standard vortices and UMZ interfaces in blocking diffusive momentum transport, which suggests our momentum barriers are physical features that may be the cause of coherence signatures in statistical and non-objective diagnostics. We also introduce normalized trajectory metrics that provide unprecedented visualizations of objective coherent structures by avoiding strong turbulence biases.en_US
dc.identifier.citationAksamit, N., & Haller, G. (2022). Objective momentum barriers in wall turbulence. Journal of Fluid Mechanics, 941, A3en_US
dc.identifier.cristinIDFRIDAID 2137366
dc.identifier.doi10.1017/jfm.2022.316
dc.identifier.issn0022-1120
dc.identifier.issn1469-7645
dc.identifier.urihttps://hdl.handle.net/10037/28887
dc.language.isoengen_US
dc.publisherCambridge University Pressen_US
dc.relation.journalJournal of Fluid Mechanics
dc.rights.accessRightsopenAccessen_US
dc.rights.holderCopyright 2022 The Author(s)en_US
dc.rights.urihttps://creativecommons.org/licenses/by/4.0en_US
dc.rightsAttribution 4.0 International (CC BY 4.0)en_US
dc.titleObjective Momentum Barriers in Wall Turbulenceen_US
dc.type.versionpublishedVersionen_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US
dc.typePeer revieweden_US


Tilhørende fil(er)

Thumbnail

Denne innførselen finnes i følgende samling(er)

Vis enkel innførsel

Attribution 4.0 International (CC BY 4.0)
Med mindre det står noe annet, er denne innførselens lisens beskrevet som Attribution 4.0 International (CC BY 4.0)