DPM particle tracking with eulerian multiphase flow and UDF

  • Last Post 11 July 2019
Twain posted this 11 July 2019

Hello there,

i am encountering some problems with my simulation, hopefully someone can help me sorting things out

I am modeling a multi phase eulerian flow through a porous zone, with velocity inlet, pressure outlet, SIMPLE algo and UDFs controlling the fluid flow.                           
(2 liquid, 1 gas)                           
the UDF descrbies e.g. viscouse resistance and the masstransfer between the 2 liquid zones,                           
which results in  volumefractions of those 2 liquids 'mixing' over the porous zone                           
Now i would like to track some particles through the domain and view their distribution.                           
Therefore i used DPM, particle tracking, with injection from the inlet durface.                           
    The result indicates the particles go through the porous media - but they do not seem to 'mix' as heavily as the volumefraction of the phases.                       
    So my question is:       

    In this case, do i need to       

          a) somehow assain those UDF to the injection?       
         Where as liquid 1 and 2 enter the porous zone through (surface) inlet - at first i thought this would "make"          the injected particles follow accordingly     
                        [from Limitations on Using the Discrete Phase Model with Other ANSYS Fluent Models
                            [" ...  When using the DPM model with the Eulerian multiphase model, the tracked particles rely only on the primary phase to compute drag, heat, and mass transfer.
                            Also, any DPM related source terms are applied to the primary phase. Particle tracking relative to a secondary phase is not provided. ... "]

                    If adding UDFs is nessecary, what is the recommended way of doing so?       
                    (ecspecially, as there are  UDFs for each luiqid phase)                              

                   b) use an other type of particle?       
                        e.g. inert ones?   
I hope i was able to describe the problem, even without any pictures atm.                            
Thanks in advace for your help!                           

BR Twain!


edit: formating

abenhadj posted this 11 July 2019

If massless or inert particles without coupling you can track with the phase you want as beta feature. In all other case you need to copy the velocity field into the one of primary phase and then switch back. Not easy. We are working on extending Eulerian multiphase compatibility.

Best regards,