[RSM]

Hi i am a masters student, i am new to this fluent ansys simulation.
I did a cyclone simulation with fluent ansys for my thesis research.
I tried to simulate the cyclone from wang et al 2006 journal, but when i increase the inlet speed, the efficiency decreases.
I've tried increasing the iteration value, but I haven't seen any changes yet
I tried this simulation in steady state and using the rsm model, using DPM and rosin-rammler, boundary condition that i used is velocity inlet, outflow and wall.
First order scheme for momentum equation and the turbulent kinetic energy k and the turbulent dissipation rate ε and the Reynolds stress equations were employed for spatial discretisation. The SIMPLEC algorithm was used for pressure-velocity coupling and the standard scheme for pressure discretisation.
I hope to get some suggestions
thanks in advance for the reply

[Guvennergiz]

I have 2 questions depends on your case;
1) While you saying inlet speed, do you mean there is a inlet velocity boundary condition in your case? If you say so, shouldnt be a vacuum boundary condition intead of velocity inlet in cyclones?
2) Wouldn't it be more difficult for the particles to escape the flow due to centripetal forces from high velocities? Isn't it normal for efficiency to drop for this reason?

[RSM]

Yes velocity inlet in the boundary condition
But in the journal that i was tried to simulate, the efficiency increases

[RSM]

but i was wondering, what do you mean about vacuum boundary condition, would you like to explain for me about this?
thank you for your reply

[Guvennergiz]

I wanted to mean suction while saying vacuum. On this kind of seperation systems, fluid need to be suction from dusty area. Examples are below. Thats why there should be a mass flow outlet in the cyclones actually, not mass flow inlet.

https://www.youtube.com/watch?v=pEVpF404Hu8

Sample.jpg

[RSM]

thank you for your reply