I am simulating a fluidized bed using PIC (Eulerian-Lagrangian) approach. All the particles have the same diameter and the same density. According to the manual (page 2 here), the MFiX-PIC solids model tracks the position and trajectory of computational parcels,
statistical groups of particles that share the same physical characteristics (e.g. diameter and
density):
I am confused because I am not seeing any “parcel” in the visual presentation of the model (see below). I (and you) can see each individual particle! It seems that PIC tracks each individual particle rather than grouping the particles in cell into “parcels”. Is this because the particles have the same density and the same diameter? In other words, the number of parcels is equal to the number of particles because the particles have the same density and the same diameter. Am I correct?
You are visualizing parcels, individual particles are not tracked and are not saved in the output files. A parcel looks the same as a particle (it is a sphere), but it generally has a larger size based on the number of particles per parcel, called statistical weight. For example if the statistical weight is 8, then the parcel size is twice the particle size. If the number of parcels is the same as the number of particles, this means you have set the statistical weight to 1.
Thanks for your reply. Based on what you said, I think that the statistical weight is set to 1. However, could you please tell me where I can change the statistical weight?
You can set it in the Solids pane:
This will be applied to all ICs and BCs, unless you overwrite it when you set the ICs and BCs:
You can load some ready-to-run PIC setups to get more familiar with the settings from the New Project (in Main menu):
