Learning Forum

[jeffer]

Hi there

Someone can give me an orientation about this simulation in fluent?

First. I'm trying to simulate a spiral concentrator with DPM with the next parameters:

→steady state analasys

→Gravity in Z direction: -9.81 m/s2

→Viscous model: RNG k-e model, swirl dominated flow condition

→Discrete phase model:

[John Ibrahim]

Hi Jeffer I recommend you to switch to steady tracking and make it one way interaction. That means you uncheck the interaction with the continuous phase. You need to converge the continuous phase very well do the particle tracking at the end and find out if you get the trajectories at the outlet or not. Keep in mind the particles are very small so one-way interaction is a good assumption. Try this first and let me know how it looks like. When plotting the particles, please display the outline of the bc so we can find out where the particles are stopped
Best
John

[Rob]

Also check the spiral "upper" surface. Why are you seeing flow boundary markers on it?

[jeffer]

Thanks for the suggest
I've noticed that I have problems with the models due to the particle's path show and with the velocity, because present an overflow and don't follow the spiral trajectory

[jeffer]

Thanks for your suggestions, I will try it

[Rob]

Why are the particles not penetrating into the fluid? They should follow the flow, unless you've injected them on the outlet or got gravity pointing in the wrong direction.

[jeffer]

Hi I'm still trying the simulation
First, I've injected the particles from 'inlet' with the same inlet velicity that the water
and now I turn on the multiphase and put the Eulerian, with 2 Eulerian phases; water and air, and a discrete phase; particles. In this case I got to good residuals, the problem now is that the first iterations, the particles follow the trajectory of the spiral but then they did not

First 20 iterations


20 to 550 iteration

This is the last iteration: 550
I've changed the inlet, now it's up (red line)

Any suggestion?

[Rob]

Euler multiphase and DPM don't always play well as the DPM particles don't see the second phase(s). I'd focus on why the "single" phase model isn't working as expected and go from there.