## Fluids

#### Multi phase(Euler -EULER ,TFM ) flow simulation of the reduction reaction in rotary kiln

• Prashantjikar
Subscriber

Hi,This is Prashant

I am trying to solve the multi phase flow simulation for counter current flow of Solid(ferrite Fe2O3) and reducing gas (CO)for  reduction process in rotary kiln. To solve this I am using Euler-Euler TFM simulation scheme in which primary phase is the gas(CO) phase while secondary phase is solid phase(Fe2O3)  and both phase patch. To account  the reaction species  I am using species transport reaction (Fe2O3 +2CO = 2Fe + 2CO2)(Fe and CO2 both consider as secondary species of phase3 and phase 4 respective phase mass fraction enter in the boundary condition) for radiation P1 model employed.In order to provide rotation moving wall motion given to adjacent cell with rotation speed of 5rpm. In calculation activities initially lower time step 0.01 time step 6000 for 100 iteration(I want to run this for 60 min as per experimentation).

The problem is solution not getting converged and showing following massage

1.Divergence detected in AMG solver

Reversed flow in 3 faces on pressure outlet

2.Divegence detected in AMG solver phase 1 species -3=increase relaxation sweep

3.You may try the enhanced divergence recovery with (rpsetvar ‘amg/protective-enhanced)

4.D.D. in AMG  solver –mp x momentum –decreasing coarsening size

5. D.D. in AMG  solver –mp x momentum-decresing relaxation sweep.

• Rob
Ansys Employee

Sketch out your geometry and include your boundary condition & solids location (if patched rather than flowing into the domain).  Write out what reacts with what, and in which phase.  While you're doing that, think about what you're actually trying to achieve: the above looks like a list of models but I don't actually know what you want to do.

Finally, have a look at the P1 model limitations: why did you choose to use that one?

I'll also move this to the CFD area as it's not multiphysics.

• Prashantjikar
Subscriber

Dear rwoolhou,

#### Thank you for your time and consideration and feedback for  my simulation problem. I have completed your suggestion and corrected the problem accordingly.please find the attachment hoping for positive reply.

Thank You

Kind Regards

Mr. P.C.Jikar

Simulation Goal :-

Ø      Develop  2D simulation and visualization profile for analyzing temperature ,velocity profile, mass fraction of solid species

( Fe2O3,Fe ) and gas species (CO,CO2) along the length of kiln

Reduction Reaction :-

Fe2O3     +     2CO     =      2Fe        +      2CO2

(Solid )          (Gas)           (Solid )            (Gas)

Reactant species                     Product species

P1 model limitations: why did you choose to use that one?

Include effect of scattering  and effects of particle .Radiation will takes place only in the product species Fe so I choose this. Radiation of reactant species and gaseous species neglected.

Yeah it have limitations

1.Assume all surface diffuse

2.Loose accuracy

3. Over predict the result

yeah you may move this problem to CFD section also.

• DrAmine
Ansys Employee
Is the granular phase as granular I assume? How many phases are now included? I will go with only two phases and perhaps think about DDPM if dense.
• Prashantjikar
Subscriber

Dear Amine,

Is the granular phase as granular I assume?

---Yeah granular phase is granular

How many phases are now included?

---Two phases solid(Fe2O3 and Fe) and gas(CO and CO2)  , total 4 species

I will go with only two phases and perhaps think about DDPM if dense.

---Ok, I will try to solve with DDPM .

• Prashantjikar
Subscriber

Can you please suggest tutorial or literature related to DDPM so that I can look into that  to check its simulation sensitivity to my experimental model model.

• DrAmine
Ansys Employee

I am sorry I am not aware about any standard DDPM tutorial.

• DrAmine
Ansys Employee

• Prashantjikar
Subscriber

Dear Mr.Amine,

Thank you very much for guiding and providing this tutorial.Probably this work I am trying to solve my problem with DDPM approach if any I will contact you.

Kind Regards,

P.C.Jikar