Learning Forum

[Michal Dorniak]

Hello esteemed colleagues,

 

I am currently engaged in simulating the flow of combustion air within a rotary kiln burner, along with the addition of conveying pulverized coal particles. During the simulation, I have encountered convergence issues when attempting to run the model with particles enabled. Interestingly, when I run the simulation without the discrete phase model (DPM) activated, convergence is achieved successfully.

 

The primary challenge observed is the presence of random areas with excessive velocity, the origin of which remains unclear to me. Although these areas eventually stabilize over time, new regions with similar issues arise, creating a repetitive pattern. Areas damaged by erosion should be assessed.

 

In an attempt to address this issue, I have experimented with reducing the under-relaxation factor (URF) and adjusting the time scale factor, considering that the simulation has been set as steady-state. Additionally, I have implemented particle-gas interaction to facilitate better accuracy in the simulation. The mesh should be fine. 

 

I would greatly appreciate any insights or suggestions you may have regarding this convergence problem with the presence of particles in the simulation.

 

Thank you in advance for your assistance.

 

Best regards,

Michal

[Essence]

Hello,

Please try refining the mesh in the mixing zone. I would suggest you to use multizone mesh to improve the mesh quality. Maintain the growth rate in the inflation layers and core not more than 1.2.