Difference between revisions of "Settling Sphere by Michael Alletto"
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=Sphere settling under the influence of gravity= | =Sphere settling under the influence of gravity= | ||
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| + | ==Introduction== | ||
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| + | This tutorial has two main objectives: | ||
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| + | * The '''first objective''' is to show how to set up an overset simulation with OpenFOAM. The overset methods (also know as chimera method) is very useful if large body motions have to be simulated. It consists in a fixed background mesh and one or more disconnected mesh regions which are subject to large displacements. In order to couple the disconnected mesh regions, the flow variables are interpolated between the meshes. Inside each disconnected mesh region, the solution is calculated by means of the usual finite volume discretisation. The different mesh regions are usually not subject to topological changes which allows to maintain the original mesh quality. | ||
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| + | * The '''second objective''' is to validate the overset methodology implemented into OpenFOAM with experiments. This is a mandatory step to estimate the uncertainty of a given simulation method. The uncertainty of a tool is connected to the risk not meeting a design criteria when this tool is employed in an industrial context. | ||
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| + | For this purpose the experimental setting by \cite{ten2002particle} was chosen to be simulated. The experimental settings consists in a rectangular box with dimensions of 100x100x160mm (in x-,y- and z-coordinate direction). Gravity points in negative z-direction. The lower part of the sphere was hanging 120mm from the bottom wall. The sphere had a diameter of 15mm and a density $\rho_s$ of 1120 $kg/m^3$. Different Re-numbers based on the free falling velocity were measured (Re: 1.4, 4.1, 11.6 and 32.2). For this tutorial the lowest Re number was chosen. The variation of the Re-number in the experiments was achieved by choosing fluids with different fluid viscosities $\mu_f$. The same can be done here if other Re-numbers have to be simulated. The setup can be seen in Figure \ref{fig:setup}. | ||
Revision as of 03:45, 5 September 2019
- contributor: Michael Alletto
- affiliation: ???
- contact: click here for email address
- OpenFOAM versions: v1906
- Published under: CC BY-NC-ND license ??? (creative commons licenses)
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Go back to Meshing.
Sphere settling under the influence of gravity
Introduction
This tutorial has two main objectives:
- The first objective is to show how to set up an overset simulation with OpenFOAM. The overset methods (also know as chimera method) is very useful if large body motions have to be simulated. It consists in a fixed background mesh and one or more disconnected mesh regions which are subject to large displacements. In order to couple the disconnected mesh regions, the flow variables are interpolated between the meshes. Inside each disconnected mesh region, the solution is calculated by means of the usual finite volume discretisation. The different mesh regions are usually not subject to topological changes which allows to maintain the original mesh quality.
- The second objective is to validate the overset methodology implemented into OpenFOAM with experiments. This is a mandatory step to estimate the uncertainty of a given simulation method. The uncertainty of a tool is connected to the risk not meeting a design criteria when this tool is employed in an industrial context.
For this purpose the experimental setting by \cite{ten2002particle} was chosen to be simulated. The experimental settings consists in a rectangular box with dimensions of 100x100x160mm (in x-,y- and z-coordinate direction). Gravity points in negative z-direction. The lower part of the sphere was hanging 120mm from the bottom wall. The sphere had a diameter of 15mm and a density $\rho_s$ of 1120 $kg/m^3$. Different Re-numbers based on the free falling velocity were measured (Re: 1.4, 4.1, 11.6 and 32.2). For this tutorial the lowest Re number was chosen. The variation of the Re-number in the experiments was achieved by choosing fluids with different fluid viscosities $\mu_f$. The same can be done here if other Re-numbers have to be simulated. The setup can be seen in Figure \ref{fig:setup}.
