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IDProjectCategoryView StatusLast Update
0002969OpenFOAMBugpublic2018-06-03 10:01
Reportermpezhu Assigned Tohenry  
PrioritylowSeverityminorReproducibilityalways
Status closedResolutionunable to reproduce 
PlatformGNU/LinuxOSOpenSuSEOS Version12.3
Summary0002969: particle dispersion in a pulverized coal combustion
DescriptionHello,

We are using coalChemistryFoam solver to simulate a pulverized coal combustion in a semi-industrial furnace with RAS. All the numerics are consistent with those in the tutorial files, i.e. system/ and constant/. As first test, we inject inert coal particles into the furnace, i.e. without gas phase combustion, devolatilization and char combustion, no radiation either. The OpenFOAM version is 2.3.0.

However, for the spatial distribution of coal particles in the furnace. we found that the coal particles always disperse preferentially towards one direction (y direction, one of the spanwise direction) at some streamwise locations. This furnace can be viewed as being symmetric. Therefore, we expect that the distributions of the coal particles should be symmetric as well. No physical mechanisms can support this kind of asymmetry. We add the gravity accerleration as (0 -9.81 0), but we do not think this is the source of the problem.

We guess this may be related to the "dispersionModel" for coal particles. We always use "stochasticDispersionRAS", same as that used in the tutorial. However, when I read the code for the dispersion models, I did not find any problem for it.

Also, the gas phase velocity is normal and correct.

I attached some figures and coalCloud1Properties file in this thread. Could you please give some comments about this issue?

Thanks a lot!
TagsNo tags attached.

Activities

mpezhu

2018-06-03 03:45

reporter  

figure.zip (608,496 bytes)

mpezhu

2018-06-03 04:00

reporter   ~0009694

we also tried another dispersion model "gradientDispersionRAS", but the results are almost similar.

However, when we use "none" for the dispersion model, the particle shows very limited dispersion and always goes along the central gas stream.

henry

2018-06-03 09:42

manager   ~0009695

> The OpenFOAM version is 2.3.0.

You will need start by upgrading to OpenFOAM-5.x or better OpenFOAM-dev.

mpezhu

2018-06-03 09:49

reporter   ~0009696

Thanks! I have compared the source files "stochasticDispersionRAS.C" in OF2.3.0 and 5.0.

The biggest difference is how to predict the directional vector dir. So this is the problem? Can we implement the same way for dir prediction in 2.3.0 as that in 5.0?

Thanks.

henry

2018-06-03 10:01

manager   ~0009697

We provide support for the latest versions of OpenFOAM, please upgrade to OpenFOAM-5.x or OpenFOAM-dev and the follow the bug reporting rules:

https://bugs.openfoam.org/rules.php

Issue History

Date Modified Username Field Change
2018-06-03 03:45 mpezhu New Issue
2018-06-03 03:45 mpezhu File Added: figure.zip
2018-06-03 04:00 mpezhu Note Added: 0009694
2018-06-03 09:42 henry Note Added: 0009695
2018-06-03 09:43 henry Priority high => low
2018-06-03 09:43 henry Severity major => minor
2018-06-03 09:49 mpezhu Note Added: 0009696
2018-06-03 10:01 henry Note Added: 0009697
2018-06-03 10:01 henry Assigned To => henry
2018-06-03 10:01 henry Status new => closed
2018-06-03 10:01 henry Resolution open => unable to reproduce