The similarity theory of free turbulent shear flows of viscoelastic fluids

• Tipo: Artigo em Revista Científica Internacional
• Data: 2024

Autores

M. C. Guimarães (Autor) Outra; F. T. Pinho (Autor) FEUP; C. B. da Silva (Autor) Outra

Revista

Título: Journal of Non-Newtonian Fluid Mechanics

Vol. 323

Página Inicial: 105148

ISSN: 0377-0257

Editora: Elsevier

Indexação

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Outras Informações

ID Authenticus: P-00Z-KBX

DOI: 10.1016/j.jnnfm.2023.105148

Abstract (EN): A new theory is formulated for the description of the conformation state of the polymer chains in free turbulent shear flows of viscoelastic fluids. Using self-similarity arguments and new scaling relations for the turbulent flux of conformation tensor we show the existence of minimum and maximum solvent dissipation reduction asymptotes, and four different polymer deformation regimes. The similarities with the maximum drag reduction asymptote of turbulent pipe flow is discussed and new scaling laws are obtained for all components of the mean conformation tensor at each deformation regime. Analytical solutions for the self-similar transverse profiles of the conformation tensor components are also obtained, providing the complete solution for the mean flow problem at the far field. The analysis is developed for both planar jets and wakes and covers the two limits of shear flows, with large and small velocity differences, respectively. Comparisons of the new theoretical results with several direct numerical simulations employing the FENE-P rheological model show excellent agreement.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 24