Stability of a Buoyant Oldroyd-B Flow Saturating a Vertical Porous Layer with Open Boundaries

The performance of several engineering applications are strictly connected to the rheology of the working fluids and the Oldroyd-B model is widely employed to describe a linear viscoelastic behaviour. In the present paper, a buoyant Oldroyd-B flow in a vertical porous layer with permeable and isothe...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Stefano Lazzari, Michele Celli, Antonio Barletta
Formato:	article
Lenguaje:	EN
Publicado:	MDPI AG 2021
Materias:	buoyant convection porous medium Oldroyd-B viscoelastic fluid linear stability analysis open boundary Thermodynamics QC310.15-319 Descriptive and experimental mechanics QC120-168.85
Acceso en línea:	https://doaj.org/article/b6c2417c29a144648dcb36fd43bdd12e
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:b6c2417c29a144648dcb36fd43bdd12e
record_format	dspace
spelling	oai:doaj.org-article:b6c2417c29a144648dcb36fd43bdd12e2021-11-25T17:31:23ZStability of a Buoyant Oldroyd-B Flow Saturating a Vertical Porous Layer with Open Boundaries10.3390/fluids61103752311-5521https://doaj.org/article/b6c2417c29a144648dcb36fd43bdd12e2021-10-01T00:00:00Zhttps://www.mdpi.com/2311-5521/6/11/375https://doaj.org/toc/2311-5521The performance of several engineering applications are strictly connected to the rheology of the working fluids and the Oldroyd-B model is widely employed to describe a linear viscoelastic behaviour. In the present paper, a buoyant Oldroyd-B flow in a vertical porous layer with permeable and isothermal boundaries is investigated. Seepage flow is modelled through an extended version of Darcy’s law which accounts for the Oldroyd-B rheology. The basic stationary flow is parallel to the vertical axis and describes a single-cell pattern where the cell has an infinite height. A linear stability analysis of such a basic flow is carried out to determine the onset conditions for a multicellular pattern. This analysis is performed numerically by employing the shooting method. The neutral stability curves and the values of the critical Rayleigh number are evaluated for different retardation time and relaxation time characteristics of the fluid. The study highlights the extent to which the viscoelasticity has a destabilising effect on the buoyant flow. For the limiting case of a Newtonian fluid, the known results available in the literature are recovered, namely a critical value of the Darcy–Rayleigh number equal to 197.081 and a corresponding critical wavenumber of 1.05950.Stefano LazzariMichele CelliAntonio BarlettaMDPI AGarticlebuoyant convectionporous mediumOldroyd-B viscoelastic fluidlinear stability analysisopen boundaryThermodynamicsQC310.15-319Descriptive and experimental mechanicsQC120-168.85ENFluids, Vol 6, Iss 375, p 375 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	buoyant convection porous medium Oldroyd-B viscoelastic fluid linear stability analysis open boundary Thermodynamics QC310.15-319 Descriptive and experimental mechanics QC120-168.85
spellingShingle	buoyant convection porous medium Oldroyd-B viscoelastic fluid linear stability analysis open boundary Thermodynamics QC310.15-319 Descriptive and experimental mechanics QC120-168.85 Stefano Lazzari Michele Celli Antonio Barletta Stability of a Buoyant Oldroyd-B Flow Saturating a Vertical Porous Layer with Open Boundaries
description	The performance of several engineering applications are strictly connected to the rheology of the working fluids and the Oldroyd-B model is widely employed to describe a linear viscoelastic behaviour. In the present paper, a buoyant Oldroyd-B flow in a vertical porous layer with permeable and isothermal boundaries is investigated. Seepage flow is modelled through an extended version of Darcy’s law which accounts for the Oldroyd-B rheology. The basic stationary flow is parallel to the vertical axis and describes a single-cell pattern where the cell has an infinite height. A linear stability analysis of such a basic flow is carried out to determine the onset conditions for a multicellular pattern. This analysis is performed numerically by employing the shooting method. The neutral stability curves and the values of the critical Rayleigh number are evaluated for different retardation time and relaxation time characteristics of the fluid. The study highlights the extent to which the viscoelasticity has a destabilising effect on the buoyant flow. For the limiting case of a Newtonian fluid, the known results available in the literature are recovered, namely a critical value of the Darcy–Rayleigh number equal to 197.081 and a corresponding critical wavenumber of 1.05950.
format	article
author	Stefano Lazzari Michele Celli Antonio Barletta
author_facet	Stefano Lazzari Michele Celli Antonio Barletta
author_sort	Stefano Lazzari
title	Stability of a Buoyant Oldroyd-B Flow Saturating a Vertical Porous Layer with Open Boundaries
title_short	Stability of a Buoyant Oldroyd-B Flow Saturating a Vertical Porous Layer with Open Boundaries
title_full	Stability of a Buoyant Oldroyd-B Flow Saturating a Vertical Porous Layer with Open Boundaries
title_fullStr	Stability of a Buoyant Oldroyd-B Flow Saturating a Vertical Porous Layer with Open Boundaries
title_full_unstemmed	Stability of a Buoyant Oldroyd-B Flow Saturating a Vertical Porous Layer with Open Boundaries
title_sort	stability of a buoyant oldroyd-b flow saturating a vertical porous layer with open boundaries
publisher	MDPI AG
publishDate	2021
url	https://doaj.org/article/b6c2417c29a144648dcb36fd43bdd12e
work_keys_str_mv	AT stefanolazzari stabilityofabuoyantoldroydbflowsaturatingaverticalporouslayerwithopenboundaries AT michelecelli stabilityofabuoyantoldroydbflowsaturatingaverticalporouslayerwithopenboundaries AT antoniobarletta stabilityofabuoyantoldroydbflowsaturatingaverticalporouslayerwithopenboundaries
_version_	1718412247932338176

Stability of a Buoyant Oldroyd-B Flow Saturating a Vertical Porous Layer with Open Boundaries

Ejemplares similares