Difference between revisions of "Bubble growth detachment influence temporal spacial resolution Michael Alletto"
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In this tutorial we will examine the influence of the grid size and the Courant number on the flow of a bubble detaching from a flat surface. In a previous tutorial (see https://wiki.openfoam.com/Bubble_growth_detachment_influence_BC_domain_size_by_Michael_Alletto) we have analyzed the influence of the boundary conditions and the domain size on the same configuration considered here. In the previous tutorial we concluded that a domain radius of approximately 10 pipe diameter from which the bubble is released is enough to have near domain size independent solutions. Furthermore we found a suitable set of boundary conditions for which the flow we analyzed behaves as expected. This two investigation should always be done as first sensitivity studies when approaching a new configuration where one is not sure of the settings to choose. The next step to investigate a new problem should be to check the influence of the grid size and the time step size (in this case we will analyze the influence of the maximum Courant number). | In this tutorial we will examine the influence of the grid size and the Courant number on the flow of a bubble detaching from a flat surface. In a previous tutorial (see https://wiki.openfoam.com/Bubble_growth_detachment_influence_BC_domain_size_by_Michael_Alletto) we have analyzed the influence of the boundary conditions and the domain size on the same configuration considered here. In the previous tutorial we concluded that a domain radius of approximately 10 pipe diameter from which the bubble is released is enough to have near domain size independent solutions. Furthermore we found a suitable set of boundary conditions for which the flow we analyzed behaves as expected. This two investigation should always be done as first sensitivity studies when approaching a new configuration where one is not sure of the settings to choose. The next step to investigate a new problem should be to check the influence of the grid size and the time step size (in this case we will analyze the influence of the maximum Courant number). | ||
This two parameters are intrinsically connected to the discretization errors made. Ideally the error made compared to a known solution will approach to zero when the grid size and time step size becomes small enough (of course only if we solve the correct equation an we do not make any modeling errors). Since in our case we do not have an exact analytical solution, we expect that the change of the variable of interest (the detachment time of the bubble) will not substantially change if the grid size and time step size are small enough. | This two parameters are intrinsically connected to the discretization errors made. Ideally the error made compared to a known solution will approach to zero when the grid size and time step size becomes small enough (of course only if we solve the correct equation an we do not make any modeling errors). Since in our case we do not have an exact analytical solution, we expect that the change of the variable of interest (the detachment time of the bubble) will not substantially change if the grid size and time step size are small enough. | ||
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| + | ==Simulation setup== | ||
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| + | ==References== | ||
| + | |||
| + | [1] Fadl Moukalled, L Mangani, Marwan Darwish, et al. The finite volume | ||
| + | method in computational fluid dynamics, volume 113. Springer, 2016. | ||
| + | |||
| + | [2] Stéphane Popinet. Numerical models of surface tension. Annual Review | ||
| + | of Fluid Mechanics, 50:49–75, 2018. | ||
| + | |||
| + | [3] Henning Scheufler and Johan Roenby. Twophaseflow: An openfoam | ||
| + | based framework for development of two phase flow solvers. arXiv | ||
| + | preprint arXiv:2103.00870, 2021. | ||
Revision as of 06:24, 22 May 2021
- contributor: Michael Alletto
- affiliation: WRD MS
- contact: click here for email address
- OpenFOAM versions: v2012
- Published under: CC BY-NC-ND license (creative commons licenses)
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Contents
Bubble growth detachment influence spacial and temporal resolution
You can download the case files [1] here.
Introduction
In this tutorial we will examine the influence of the grid size and the Courant number on the flow of a bubble detaching from a flat surface. In a previous tutorial (see https://wiki.openfoam.com/Bubble_growth_detachment_influence_BC_domain_size_by_Michael_Alletto) we have analyzed the influence of the boundary conditions and the domain size on the same configuration considered here. In the previous tutorial we concluded that a domain radius of approximately 10 pipe diameter from which the bubble is released is enough to have near domain size independent solutions. Furthermore we found a suitable set of boundary conditions for which the flow we analyzed behaves as expected. This two investigation should always be done as first sensitivity studies when approaching a new configuration where one is not sure of the settings to choose. The next step to investigate a new problem should be to check the influence of the grid size and the time step size (in this case we will analyze the influence of the maximum Courant number). This two parameters are intrinsically connected to the discretization errors made. Ideally the error made compared to a known solution will approach to zero when the grid size and time step size becomes small enough (of course only if we solve the correct equation an we do not make any modeling errors). Since in our case we do not have an exact analytical solution, we expect that the change of the variable of interest (the detachment time of the bubble) will not substantially change if the grid size and time step size are small enough.
Simulation setup
References
[1] Fadl Moukalled, L Mangani, Marwan Darwish, et al. The finite volume method in computational fluid dynamics, volume 113. Springer, 2016.
[2] Stéphane Popinet. Numerical models of surface tension. Annual Review of Fluid Mechanics, 50:49–75, 2018.
[3] Henning Scheufler and Johan Roenby. Twophaseflow: An openfoam based framework for development of two phase flow solvers. arXiv preprint arXiv:2103.00870, 2021.
