DDPM for EDEM-Fluent coupling

Megan_j

Hello,

I was wondering if anyone knows the difference between enabling and not-enabling the "Use DDPM" option in the Fluent-EDEM coupling, and when it should be enabled?

From my current understanding, it should be enabled when the discrete phase from EDEM is dense, but I was wondering if there is a minimum volume fraction or number of particles where this setting should be enabled? Will there be any errors if it is left unchecked?

Thank you.

Regards,

Megan

Mahdi_22303

I think when you use the Dicerete phase model (DPM), the particles in the domain are considered point masses in Fluent. The trajectory of particles is found using Lagrangian approach. If you are solving dilute suspension of particles for example, DPM can be used. 

When you are using DDPM, the volume fraction of particles in a CFD cell is taken into account and change the Navier-Stokes equations for fluid, and also for particles. The particles are treated as Eulerian phase as well, and a separate Eulerian phase model is used for particles. So, if you are modeling a packed bed motion of particles, DDPM must be used. 

The transition from DPM to DDPM must happen when the discrete phase occupies more than 10 percent of the CFD cell. 

If you have access to Ansys help document, you can see DDPM equations here.

https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v232/en/flu_th/flu_th_sec_ddpm.html?q=DDPM