View Issue Details
ID | Project | Category | View Status | Date Submitted | Last Update |
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0000764 | OpenFOAM | Bug | public | 2013-03-05 02:46 | 2015-01-29 09:49 |
Reporter | Assigned To | henry | |||
Priority | normal | Severity | minor | Reproducibility | always |
Status | closed | Resolution | no change required | ||
OS | Ubuntu | OS Version | 204.1 LTS | ||
Summary | 0000764: Worng evaulation of laminar viscosity nu() in cavitatingFoam | ||||
Description | I've tried to solve a cavitating flow by using cavitatingFoam. Until now, it always crashes --. When checking the code, I found one thing, which seems a bug! In cavitatingFoam, nu() seems to be calculated by using "twoPhaseMixture" class. "twoPhaseMixture" class reads transportProperties and returns nu() to turbulence. Anyway, in twoPhaseMixture, nu() value depends on "alpha". In this case, alpha=1 means pure liquid, alpha=0 does pure gas for example. In the case of cavitatingFoam, however, gamma=0 represents for pure liquid. What I mean is that alpha and gamma has exactly different meaning. When I checked nu() field for tutorial "trottle", surely worng nu() values could be obtained. Gas viscosity values exist in the region of gamma=0 (pure liquid). I always appreciate your efforts! Thanks in advance. Scurry | ||||
Tags | No tags attached. | ||||
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twoPhaseMixture does not make any assumptions about which phase is gas and which is liquid, in fact they could both be gas or both liquid. The phase properties for each phase are set in the transportProperties dictionary. |
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Thanks for your kind explanation. Yes, I understand what you're saying. And I should change the transport properties of two phases according to gamma-definition. Then, It'll be a good idea to modify all transportProperties in cavitatingFoam-tutorials. best regards Scurry |
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What is wrong with the transportProperties in the cavitatingFoam tutorials? |
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After trying to look at this bug report from a few of several possible perspectives, most of them assuming there was a communication/report issue, I have deduced that this issue has already been resolved at least since OpenFOAM 2.3.0 was released. My best hypothesis is that the confusion is revealed by the following commands: ~/OpenFOAM/OpenFOAM-2.1.x/tutorials/multiphase/cavitatingFoam$ grep -r gamma * les/throttle/system/controlDict: gamma les/throttle/0/p: gamma 1; les/throttle/0/gamma: object gamma; les/throttle3D/system/controlDict: gamma les/throttle3D/0/p: gamma 1; les/throttle3D/0/gamma: object gamma; les/throttle3D/0.org/p: gamma 1; les/throttle3D/0.org/gamma: object gamma; ras/throttle/0/p: gamma 1; ras/throttle/0/gamma: object gamma; Versus: ~/OpenFOAM/OpenFOAM-2.3.x/tutorials/multiphase/cavitatingFoam$ grep -r gamma * les/throttle/0/p: gamma 1; les/throttle3D/0.org/p: gamma 1; ras/throttle/0/p: gamma 1; Therefore, there is no longer ambiguity of gamma versus alpha. |
Date Modified | Username | Field | Change |
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2013-03-05 02:46 |
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New Issue | |
2013-03-05 16:53 | henry | Note Added: 0001956 | |
2013-03-06 09:24 |
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Note Added: 0001957 | |
2013-03-06 09:52 | henry | Note Added: 0001958 | |
2015-01-27 22:30 | wyldckat | Note Added: 0003599 | |
2015-01-27 23:29 | henry | Status | new => closed |
2015-01-27 23:29 | henry | Assigned To | => henry |
2015-01-27 23:29 | henry | Resolution | open => no change required |