Heat and mass transfer computations for laminar flow in an axisymmetric sudden expansion

Fletcher, David F.; Maskell, S. J.; Michael, Patrick

doi:10.1016/0045-7930(85)90026-x

Cited by 31 publications

(17 citation statements)

References 6 publications

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“…Hence, plane sudden expansion flows could be subjected to different types of inflow profiles. The effect of the type of the inflow velocity profile on the flow in an axisymmetric expansion was studied by Fletcher et al [22]. No studies, however, investigated the effect of the type of inflow profile on the onset of bifurcation.…”

Section: Introductionmentioning

confidence: 97%

Iterative solvers and inflow boundary conditions for plane sudden expansion flows

Wahba

2007

Applied Mathematical Modelling

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Incompressible laminar flow in a symmetric plane sudden expansion is studied numerically. The flow is known to exhibit a stable symmetric solution up to a critical Reynolds number above which symmetry-breaking bifurcation occurs. The aim of the present study is to investigate the effect of using different iterative solvers on the calculation of the bifurcation point. For this purpose, the governing equations for steady two-dimensional incompressible flow are written in terms of a stream function-vorticity formulation. A second order finite volume discretization is applied. Explicit and implicit solvers are used to solve the resulting system of algebraic equations. It is shown that the explicit solver recovers the stable asymmetric solution, while the implicit solver can recover both the unstable symmetric solution or the stable asymmetric solution, depending on whether the initial guess is symmetric or not. It is also found that the type of inflow velocity profile, whether uniform or parabolic, has a significant effect on the onset of bifurcation as uniform inflows tend to stabilize the symmetric solution by delaying the onset of bifurcation to a higher Reynolds number as compared to parabolic inflows.

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Section: Introductionmentioning

confidence: 97%

Iterative solvers and inflow boundary conditions for plane sudden expansion flows

Wahba

2007

Applied Mathematical Modelling

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“…Badekas and Knight [3] later concluded that the linear dependence of the reattachment length on Re is valid even at a high expansion ratio of 6.0. Fletcher et al [4] and Guo et al [5] studied the flow hydrodynamics to discuss the effects of the expansion ratio with focus on the heat and mass transfer phenomena associated with sudden expansion. Their conclusion was that the reattachment length decreases with the heat addition.…”

Section: Introductionmentioning

confidence: 99%

On the eddy characteristics of laminar axisymmetric flows through confined annular geometries with inward expansion

Nag

Datta

2007

Proceedings of the Institution of Mechanical Engineers, Part C:

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In this paper, laminar flows through axisymmetric confined annular geometries with sudden expansions have been studied numerically using a third-order accurate upstream biased quadratic scheme to investigate the recirculating eddy characteristics, following the expansion, in terms of recirculation length and eddy intensity. Two variations of annular geometry have been considered. In the first geometry, a smaller annulus abruptly expands inwardly into a larger one, whereas in the second case an abrupt inward expansion of the smaller annulus leads to a coaxial pipe. Fully developed inflow has been observed to separate immediately after the expansion plane forming a recirculating eddy. The variations in the size and intensity of the recirculating eddy are studied at different Reynolds numbers and expansion ratio for both the geometries. The effect of the presence of an inner solid wall after the expansion plane on the behaviour of the eddy is investigated. A secondary wall recirculation has been observed under specific flow situations in both the geometries. The characteristics of the secondary eddy have also been analysed and compared.

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“…Both experimental and numerically calculated values of the above parameters in the case of flow through an expanding pipe geometry are available in a host of literature, e.g. [38][39][40][41][42][43]. The present code is validated by comparing the calculated values of the above-mentioned parameters with the published data from the literature at different expansion ratios ER (=D/d) and Reynolds numbers (Figs 4(a) to (d)).…”

Section: Code Validationmentioning

confidence: 89%

Steady laminar flow of blood through successive restrictions in circular conduits of small diameter

Nag

Datta

2008

Proceedings of the Institution of Mechanical Engineers, Part C:

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In this paper, numerical results on steady laminar flow of blood through an artery having two successive identical axisymmetric restrictions are presented, at varying degrees of restrictions. Physically, such a flow has features in common with steady blood flow through an artery with multiple stenoses. Additionally, results are presented for the blood flow through an artery in the presence of a single restriction, for comparison. The artery has been modelled as a tube with a rigid wall. The rheological characteristics of blood have been assumed both as Newtonian and non-Newtonian. Three different non-Newtonian models of blood -power law, Quemada, and Carreau-Yasuda models -have been considered in the analysis. The haemodynamic effects of the restrictions on the axial velocity distribution, recirculation zones formed downstream to the restrictions, the wall shear stress, and the pressure drop in the artery have been analysed. The irreversible pressure loss coefficient is calculated from the pressure drop and its variation with the degree of stenosis is obtained.

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Heat and mass transfer computations for laminar flow in an axisymmetric sudden expansion

Cited by 31 publications

References 6 publications

Iterative solvers and inflow boundary conditions for plane sudden expansion flows

Iterative solvers and inflow boundary conditions for plane sudden expansion flows

On the eddy characteristics of laminar axisymmetric flows through confined annular geometries with inward expansion

Steady laminar flow of blood through successive restrictions in circular conduits of small diameter

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