Hi, does anyone know how to calculate cyclone seperator(gas-solid flow) in cfx. Is it better to choose Eular-Eular methods or Lagrange methods?I have choosed particle transport,But I can't find the massflow of particles at outlet, how can I get it. Thanks in advance!

Lawrence

Dear lawrence,

I just done such simulation on CFX5.5 using Euler/Euler model.

I works quite well now with very nice results regarding mass fraction which are in good qualitative agreement with our experiments.

Euler/lagrange will also works fine for this kind of flow because the dispersed phase has a very low volume fraction in most cyclone so particle/particle interaction can be neglected. It is often an easier way to simulation cyclone flow.

I am not sure of what you are talking about massflow of particles. Is it a solution problem (imbalance in particle mass flow) or a post processing problem.

I will be glad to help you if you have any question

Best regards

Alain

Thank for your help!

Yes,I have tried to use the Eular-Eular methods of CFX5.5. What I have done is for Dust Precipitator, something like cyclone. there is 50 percent ash(massfraction) in the inflow air, about 1.88 percent volume fraction, speed 2 m/s. I have choosed bouyancy flow, schiller-naumann drag model. But I find that it is difficult to convergence, The convergence history is too noise. The RMS residuals keep at 1.0e-2.

I also tried the Eular-lagrange methods in CFX4, I can only plot the track file(the track), and can't find the massflow of the particles on the outlet .

By the way, Do you consider the bouyancy force in calculation?

Considering the calculation I am doing, Which methods, do you think is better?

Thanks in Advance.

Have you tried to look at the tracks in a postprocessor ? A reason why you do not see any particle at the outlet could be that they get trapped, stopped after certain time or timestep or you are using that the particle sticks to the wall. Try to look in the track file to see why they are stopped and look at the tracks. Just some hints, hope they help Regards Jan

[tom_smith_2012]

Hi，
everyone.
I'm recently having a headache about a solid-liquid cyclone modeling with CFX12. When I used SSG RSM model to calculate the flow filed, some problems occured. I browsed all the thread about cyclone on this forum, but I still unsolve this problem, even new problems came.
I hope some ideas, thank you!!
This is the link:
http://www.cfd-online.com/Forums/cfx...g-problem.html

[ghorrocks]

You won't get much help if you don't explain what your problem is.

But guessing from your other thread the problem is convergence. I have already said what you need to do here - RSM models are very demanding for mesh quality. You will need to remesh with a higher quality mesh.