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|ID||Project||Category||View Status||Date Submitted||Last Update|
|0002605||OpenFOAM||Bug||public||2017-07-06 15:49||2017-07-10 18:04|
|Platform||Linux||OS||OpenSuSE||OS Version||Leap 42.1|
|Summary||0002605: tutorial hotBoxes: different results from OF-2.3.x to OF-dev|
running ./Allrun-parallel in tutorial "hotBoxes" of OF-2.3.x seems to give physically reasonable results, liquid film temperatures up to 349 K and retrained droplets have higher temperatures than 300 K. In OF-dev the liquid film and the droplets remain cold. Heat transfer from the hotBoxes to the liquid film do not occure. Maximum liquid film temperatures around 301 K. See attached figures.
the same issue was reported earlier for OF2.1.x -> OF2.3.x (see ID 0001207) and was resolved doing "thermoSingleLayer: Revert q back to the working version in OpenFOAM-2.1.x"
|Steps To Reproduce||execute ./Allrun-parallel in hotBoxes-tutorial of OF-2.3.x and OF-dev|
|Tags||No tags attached.|
hotBoxesFigures.zip (95,925 bytes)
||How recent is the OpenFOAM-dev you are using?|
last git pull on 28.06.2017 14:40
I've added a relationship to the report I did last year (#2179) on a related topic, although at the time it referred to OpenFOAM 4.x.
A summary of that report: the modelling was improved on the film heat-transfer implementation for OpenFOAM 4.x/dev, but unfortunately the affected tutorials were not updated to give similar results to the ones in 3.0.x and older.
Since that report, I haven't managed to understand how this tutorial case (and sibling cases) can be adapted to have similar set-ups to give similar results to the past versions.
@andre: For what time snapshot are those figures that you attached?
snapshots were taken at t=1.2 s
I have found the problem, it is in the handling of the "alpha" field which is the indicator for the presence of the film which I use to filter the heat transfer to avoid instability when the film is VERY thin. The problem is that "alpha" is also adjusted for hydrophilic and hydrophobic surfaces so includes other physics:
if ((alpha_[i] < 0.5) && (delta_[i] > hydrophilicWet))
alpha_[i] = 1.0;
else if ((alpha_[i] > 0.5) && (delta_[i] < hydrophilicDry))
alpha_[i] = 0.0;
which should probably be in a separtate field.
I have constructed an "alpha" without the hydrophilic/phobic switching for the c0heat transfer filtering and pushed the change:
If it works OK for a range of cases I will make the same change to 4.x and 3.0.x.
Resolved in OpenFOAM-4.x by c989277b5e4895c60f985bb4dfd412ea8aa9916b
Resolved in OpenFOAM-dev by 784d28d4404856ff744991d92b25e0a6b43d15c9
|2017-07-06 15:49||andre||New Issue|
|2017-07-06 15:49||andre||File Added: hotBoxesFigures.zip|
|2017-07-06 15:57||henry||Note Added: 0008355|
|2017-07-06 16:55||andre||Note Added: 0008356|
|2017-07-06 17:58||wyldckat||Relationship added||related to 0002179|
|2017-07-06 18:07||wyldckat||Note Added: 0008357|
|2017-07-07 08:22||andre||Note Added: 0008361|
|2017-07-10 08:29||henry||Note Added: 0008372|
|2017-07-10 18:04||henry||Assigned To||=> henry|
|2017-07-10 18:04||henry||Status||new => resolved|
|2017-07-10 18:04||henry||Resolution||open => fixed|
|2017-07-10 18:04||henry||Fixed in Version||=> 4.x|
|2017-07-10 18:04||henry||Note Added: 0008378|