Learning Forum

[Joan Rico]

Hello, 

I am running a transient simulation on ANSYS Fluent, tranking pollution particles through a DPM model.

On this regard I have a couple questions:

1,  I define the tranking of particles by the following line:
/define/models/dpm/numerics/tracking-parameters 50000 yes 3000
As far as I understood by reading the documentation, the tracking of the particles should be done until each of the particles has been travelling in my domain during 50000 time steps, right?
I was surprised that with a time step of 0.01s, and after 1000s of simulation, no particles were discarded... I paste here a part of the output:  Advancing DPM injections ....
number tracked = 2375245, escaped = 13
Flow time = 1021.52s, time step = 102152

What could be an explanation for this?

 

2.  On the same simulation, I wanted to simulate the injection of particles during a certain time and the continue the simulation for a few extra minutes to see how they are trasported.
I define the injection according to the following command line: 
/define/models/dpm/injections/create-injection injection_pollutants no yes surface no stack () no yes yes no 1 0.0375 no no no yes yes constant-mass 1e-08 no 3e-07 0 3600 profile "average-velocity-stack(scen5)" profile "soot-left(scen5)"
My imported data are the exhaust speed and the mass released into my domain. Both have 2700 rows, which refers to the aforementioned data for 2700 s, giving a diferent value per second. 

My question is: if i defined in the command a Stop Time of 3600s, what happens once we reach 2700s? Does the software restart the input data again for row 1? Does it keep the last row value constant? Or does it stop releasing particles? I ask because in my simulation I keep seeing particles coming out of the stack, and I was not undestanding what is the expected behaviour.

Thank you very much for your time and response. 

Have a nice day, 

Joan

[Prashanth]

Hello Joan,

No incomplete particles means no paticles has crossed the 50,000 threshold. You have a very large length scale anyways.

I would recommend creating an injection file for this.

[Joan Rico]

Hello Prashanth, 

Could you develop your answer a bit further? 

Thanks in advance.