A length scale for non-local multi-scale gradient interactions in isotropic turbulence

Perez Encinar, Miguel

Publication:
A length scale for non-local multi-scale gradient interactions in isotropic turbulence

dc.affiliation.dpto	UC3M. Departamento de Ingeniería Aeroespacial	es
dc.affiliation.grupoinv	UC3M. Grupo de Investigación: Ingeniería Aeroespacial	es
dc.contributor.author	Perez Encinar, Miguel
dc.date.accessioned	2024-01-30T15:15:59Z
dc.date.available	2024-01-30T15:15:59Z
dc.date.issued	2023-09-22
dc.description.abstract	Three-dimensional turbulent flows enhance velocity gradients via strong nonlinear interactions of the rate-of-strain tensor with the vorticity vector, and with itself. For statistically homogeneous flows, their total contributions to gradient production are related to each other by conservation of mass, and so are the total enstrophy and total dissipation. However, locally, they do not obey this relation and have different (often extreme) values, and for this reason both production mechanisms have been subject to numerous studies, often decomposed into multi-scale interactions. In general lines, their dynamics and contributions to the cascade processes and turbulent kinetic dissipation are different, which poses a difficulty for turbulence modelling. In this paper, we explore the consequence of the `Betchov¿ relations locally, and show that they implicitly define a length scale. This length scale is found to be approximately three times the size of the turbulent structures and their interactions. It is also found that, while the non-locality of the dissipation and enstrophy at a given scale comes mostly from larger scales that do not cancel, the non-local production of strain and vorticity comes from multi-scale interactions. An important consequence of this work is that isotropic cascade models need not distinguish between vortex stretching and strain self-amplification, but can instead consider both entities as part of a more complex transfer mechanism, provided that their detailed point value is not required and a local average of reasonable size is sufficient.	en
dc.format.extent	12
dc.identifier.bibliographicCitation	Encinar, M. P. (2023). A length scale for non-local multi-scale gradient interactions in isotropic turbulence. Journal of Fluid Mechanics, 971, A40. doi:10.1017/jfm.2023.706	en
dc.identifier.doi	https://doi.org/10.1017/jfm.2023.706
dc.identifier.issn	0022-1120
dc.identifier.publicationfirstpage	A40-1
dc.identifier.publicationissue	A40
dc.identifier.publicationlastpage	A40-12
dc.identifier.publicationtitle	Journal of Fluid Mechanics	en
dc.identifier.publicationvolume	971
dc.identifier.uri	https://hdl.handle.net/10016/39657
dc.identifier.uxxi	AR/0000033997
dc.language.iso	eng	en
dc.publisher	Cambridge University Press	en
dc.rights	© The Author(s), 2023. Published by Cambridge University Press	en
dc.rights	This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited.	en
dc.rights	Atribución-NoComercial-SinDerivadas 3.0 España	*
dc.rights.accessRights	open access	en
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/3.0/es/	*
dc.subject.eciencia	Aeronáutica	es
dc.subject.other	Isotropic turbulence	en
dc.subject.other	Turbulence theory	en
dc.subject.other	Turbulence modelling	en
dc.title	A length scale for non-local multi-scale gradient interactions in isotropic turbulence	en
dc.type	research article	en
dc.type.hasVersion	VoR	en
dspace.entity.type	Publication