Hi, everyone
I tested the new feature “define ramp for velocity” published in the version 24.1. But it seems the gas flow stopped after a period of time, as shown below.
My case file has been attached. Can you please help me check my case setting and give me some advice?
Thank you in advance for your help!
fluid_bed_tfm_3d.mfx (16.9 KB)
Are you above minimum fluidization velocity? You start with a small uniform velocity and at a void fraction of 0.5 (initial condition) that may help get the first bubble out. What happens if you use a constant value of 4m/s?
Hi, Dr. Dietiker
Thank you for your reply. My case setting partially referred to the work of Wang et al. Their work is based on MFIX-DEM. Due to large computational cost, I used MFIX-TFM here.
https://www.sciencedirect.com/science/article/pii/S1385894721052165
Hi, Dr. Dietiker
The same phenomenon occurred when I used a constant value of 4.0m/s. The gas velocity decreased gradually. It seems to be caused by other settings. But I still haven’t found out where the problem lies. It is a simple case and the parameters are not non-physical.
fluid_bed_tfm_3d.mfx (18.8 KB)
Please try the attached. I cleaned up the mesh (I like to have the stl file extend a bit past the MFiX box), increased the height of the domain to prevent solids from reaching the top, and set the particle diameter to 250 microns as in the paper.
Hi, Dr. Dietiker
Thank you for your help. Last weekend, I tested your case by using constant jet velocity and ramp jet velocity. Both of them worked well. By comparing our settings, I found the main difference is the parameters in the mesher. Can you please share you ideas on improving the mesh? Thank you.
