[wkqwkqwkq]

I tried the fluidized bed tutorial then changed the temperature to 300K everywhere to keep it isothermal. The tutorial case computes a much larger minimum fluidization velocity compared to the real value. Besides, the fluidization behaviour is completely different from Fluent two-fluid model. Have no clue where to start with.


Could anyone send me a correct twoPhaseEulerFoam fluidized bed case? Thank you.

[mnikku]

Originally Posted by wkqwkqwkq

I tried the fluidized bed tutorial then changed the temperature to 300K everywhere to keep it isothermal. The tutorial case computes a much larger minimum fluidization velocity compared to the real value. Besides, the fluidization behaviour is completely different from Fluent two-fluid model. Have no clue where to start with.


Could anyone send me a correct twoPhaseEulerFoam fluidized bed case? Thank you.

Hi,
this is quite a difficult question. I assume you have measured your minimum fluidization velocity, as there are only (more or less suitable) correlations to estimate it (for differenct material-fluidization agent pairs!).

The next problem comes from trying matching the particle size distibution in your simulations to the material you used in your experiments. And yes, there is a particle size distribution, it is a narrow or a wide one, the average particle size doesn't tell you this.

Finally regarding the simulation setup: what models you used and what are your other settings. You don't give much details so it's pretty hard to say anything about your case.

[wkqwkqwkq]

Originally Posted by mnikku

Hi,
this is quite a difficult question. I assume you have measured your minimum fluidization velocity, as there are only (more or less suitable) correlations to estimate it (for differenct material-fluidization agent pairs!).

The next problem comes from trying matching the particle size distibution in your simulations to the material you used in your experiments. And yes, there is a particle size distribution, it is a narrow or a wide one, the average particle size doesn't tell you this.

Finally regarding the simulation setup: what models you used and what are your other settings. You don't give much details so it's pretty hard to say anything about your case.

Thank you for the reply mnikku.

The particles I used is Geldart B group glass beads sizing from 425-450um. The Umf was measured around 0.14m/s and Fluent predicts this well using Gidaspow drag correlation. However, the 2.3.x twoPhaseEulerFoam predicts around 0.27m/s!!

I attached my case files, could you have a look if there is anything wrong.

https://drive.google.com/file/d/0B_F...ew?usp=sharing


Many thanks

[mnikku]

Hi,
I took a look at your files, but couldn't spot anything obviously wrong or strange (at least to my limited experience, so this doesn't confirm anything).

I ran a couple of tests with version 3.0.1 and couldn't get the bed clearly fluidized with your measured gas velocity 0.14 m/s (or with 0.15 or 0.2 m/s) (some trembling at the surface only). I currently don't have time to continue with this.

My only suggestion is to check and compare the model selection and settings between your Fluent and OpenFOAM cases to spot any differences.

Best of luck in your future endeavors!