Clustering of vector nulls in homogeneous isotropic turbulence

We analyze the vector nulls of velocity, Lagrangian acceleration, and vorticity, coming from direct numerical simulations of forced homogeneous isotropic turbulence at Reλ∈O([40-600]). We show that the clustering of velocity nulls is much stronger than those of acceleration and vorticity nulls. Thes...

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Detalles Bibliográficos
Autores: Mora, D. O., Bourgoin, M., Mininni, Pablo Daniel, Obligado, M.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2021
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/181443
Acceso en línea:http://hdl.handle.net/11336/181443
Access Level:acceso abierto
Palabra clave:TURBULENCE
MULTIPHASE FLOWS
PARTICLES
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Descripción
Sumario:We analyze the vector nulls of velocity, Lagrangian acceleration, and vorticity, coming from direct numerical simulations of forced homogeneous isotropic turbulence at Reλ∈O([40-600]). We show that the clustering of velocity nulls is much stronger than those of acceleration and vorticity nulls. These acceleration and vorticity nulls, however, are denser than the velocity nulls. We study the scaling of clusters of these null points with Reλ and with characteristic turbulence lengthscales. We also analyze datasets of point inertial particles with Stokes numbers St=0.5, 3, and 6, at Reλ=240. Inertial particles display preferential concentration with a degree of clustering that resembles some properties of the clustering of the Lagrangian acceleration nulls, in agreement with the proposed sweep-stick mechanism of clustering formation.