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August 2, 2021, 05:00 |
About limiter correction
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#1 |
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Join Date: Dec 2018
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Hello,
In official user guide(https://cfd.direct/openfoam/user-guide/v6-fvschemes/), If you can look at the figure 4.2 in the link, if the psi 1 it is corrected, if the psi is zero, meaning uncorrected. Lets look at the explanation: 'Generally the uncorrected and orthogonal schemes are only recommended for meshes with very low non-orthogonality (e.g. maximum 5∘). The corrected scheme is generally recommended, but for maximum non-orthogonality above 70∘, limited may be required' Everything, makes clear until now except this sentence :'Typically, psi is chosen to be 0.33 or 0.5, where 0.33 offers greater stability and 0.5 greater accuracy.' This sentence sounds wrong to me, i think it should be opposite. Anyway, if you can look at this link(http://www.wolfdynamics.com/wiki/tipsandtricks.pdf) at slide 25, he says that psi should be 0 for bad meshes, should be 1 for good meshed. These both sayings conflict with each other. Which one is correct or are there something that i totally miss ? Thanks |
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August 2, 2021, 07:23 |
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#2 |
Senior Member
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Location: Cologne, Germany
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i am not an expert with regards to that particular issue, but if you look closer at the slides, you see that you have basically 2 options:
1: corrected 2: limited psi on the website you have 5 entries, the entries with psi are slightly different: -> limited corrected psi maybe that 'corrected' somewhat changes what the scheme does and it is then not contradictory at all. correct me if i miss something. |
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August 2, 2021, 08:19 |
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#3 | |
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Quote:
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August 2, 2021, 09:00 |
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#4 |
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Michael Alletto
Join Date: Jun 2018
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I recommend read this book https://www.springer.com/gp/book/9783319168739
To have inside about the numerics in OF. Generally corrected means non orthogonal corrections and limited are limiters to avoid oscillation of the variables when interpolating from the cell centers to the face centers |
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August 2, 2021, 09:19 |
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#5 | |
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Quote:
Do you have any idea about my confusion ? |
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