Hello Team,
Greetings. I'm hereby attaching an image which is the pressure drop across the fluidized bed versus inlet velocity for three different cell sizes in CFD setup (rest all parameters remaining constant). Particle diameter is 1.2mm and idea is to find minimum fluidization velocity. All meshes generated by blockMesh.
Thick line corresponds to 4mmX4mmX4mm hexahedral cell. Corresponding ratio of smallestCellVolume/particleVolume = 70.73
Intermediate line corresponds to 2mmX2mmX2mm hexahedral cell. Corresponding ratio of smallestCellVolume/particleVolume = 8.842
Thin line corresponds to 1.4mmX1.4mmX1.4mm hexahedral cell. Corresponding ratio of smallestCellVolume/particleVolume = 3.0328.
CFDEM manual recommends a minimum allowed VOLUME ratio of smallest cell and biggest particle is 3. Expectation is that when this ratio is close to 3, the results are close to experiments. The expected minimum fluidization is 0.3m/s but the peak is no where to close this value and deteriorates as mesh is refined.
voidFractionModel is divided. Any suggestions / best practices are welcome.
Thank you,
Jagan Mohan.
| Attachment | Size |
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 image.jpg | 75.92 KB |
jagan1mohan | Sat, 06/06/2020 - 22:03
Particle and cell size in CFDEM
Hello Team,
Greetings. I'm hereby attaching an image (with above post) which is the pressure drop across the fluidized bed versus inlet velocity for three different cell sizes in CFD setup (rest all parameters remaining constant). Particle diameter is 1.2mm and idea is to find minimum fluidization velocity. All meshes generated by blockMesh.
Thick line corresponds to 4mmX4mmX4mm hexahedral cell. Corresponding ratio of smallestCellVolume/particleVolume = 70.73
Intermediate line corresponds to 2mmX2mmX2mm hexahedral cell. Corresponding ratio of smallestCellVolume/particleVolume = 8.842
Thin line corresponds to 1.4mmX1.4mmX1.4mm hexahedral cell. Corresponding ratio of smallestCellVolume/particleVolume = 3.0328.
CFDEM manual recommends a minimum allowed VOLUME ratio of smallest cell and biggest particle is 3. Expectation is that when this ratio is close to 3, the results are close to experiments. The expected minimum fluidization is 0.3m/s but the peak is no where to close this value and deteriorates as mesh is refined.
voidFractionModel is divided. Any suggestions / best practices are welcome.
Thank you,
Jagan Mohan.