Reevaluation of the Vertex Collocated Mesh for Primitive Variable Computation of Incompressible Fluid Flows by Enforcing Continuity-Based Boundary Conditions

Figueiredo, José Ricardo de; Oliveira, Kéteri Poliane Moraes de

doi:10.1080/10407790.2011.601184

Cited by 3 publications

(2 citation statements)

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“…As depicted in Figure 1, adjacent to the walls the staggered mesh presents irregularly spaced tangential velocity component, and the collocated mesh presents all velocity components irregularly spaced, while the semi-staggered mesh is the unique regularly spaced mesh, besides the discarded vertex collocated approach. 28,41,42 Furthermore, the semi-staggered mesh can be regular not only along coordinate axis but also in inclined walls if the aspect ratio of the mesh can be appropriately chosen, being the unique mesh that can treat a plane diverging channel in entirely regular fashion. This feature is exploited in the present work by choosing the cell aspect ratio according to the opening angle of a channel expansion.…”

Section: Finite Volume Mesh Structuresmentioning

confidence: 99%

“…The above-mentioned mesh structures were subject to a comparative study employing the cavity flow problem. 28,41,42 The staggered mesh appeared as the most stable and robust, but relatively inaccurate. Cell center collocated mesh had better accuracy at refined grids, but a high Reynolds numbers it presented abrupt changes with refinement from inaccurate to accurate patterns.…”

Section: Finite Volume Mesh Structuresmentioning

confidence: 99%

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A semi‐staggered finite volume approach applied to two‐ and three‐dimensional flow in channels with gradual expansions

Nascimento

Rodrigues

Figueiredo

2021

Numerical Methods in Fluids

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Two-and three-dimensional computations have been performed to study incompressible laminar flow of viscous fluids in symmetric channels with gradual expansions. The divergent form advective and viscous terms of Navier-Stokes equations are discretized by means of the UNIFAES scheme, which has been showing unpaired accuracy. Explicit time-wise integration allows continuity to be imposed via the Poisson equation for the pressure, solved iteratively with several iterations per velocity step in order to ensure mass conservation throughout the transient regime. The proposed finite volume approach uses the semi-staggered mesh structure, in which pressure is put at the center of the continuity cell and the velocity components at the cell vertexes. Comparative studies have shown this mesh to be highlighted by accuracy, in relation to the traditional, staggered and collocated meshes. Furthermore, it was observed that the semi-staggered mesh allowed to treat a plane diverging channel in entirely regular fashion without losing accuracy, by appropriate choice of the aspect ratio of the numerical cell, providing geometrical flexibility that does not exist in more common meshes, such as staggered and collocated structures. The present proposal explored the geometric flexibility of the semi-staggered mesh to solve with simplicity a relevant problem of a channel with gradual expansion. Overall, good agreement was observed against experimental and numerical results in the literature, therefore, it illustrates the capability of the semi-staggered approach to easily handle flat surfaces nonparallel to the coordinates axes. K E Y W O R D Sasymmetric flow, CFD, finite volumes, gradual expansion, numerical methods, semi-staggered mesh INTRODUCTIONChannels with increasing sectional area, or diffusers, are important components of devices such as valves, flow meters, and flux machines, as well as of geophysical flows and blood circulation. Due to the increasing area, the flow is decelerated, so increasing the pressure. This adverse pressure gradient may induce flow separation from walls generating recirculation regions, therefore causing high pressure losses and deteriorating the role of the channel.

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Section: Finite Volume Mesh Structuresmentioning

confidence: 99%

Section: Finite Volume Mesh Structuresmentioning

confidence: 99%