Postprocessing of particle fields

Background

It often required to perform some operations on the particles fields to obtain spatial fields (sum or average). For example, we may need to know the space-averaged velocity of particles in the simulated granular flow. For the spatial operation on the particles fields, the space is divided into some rectilinear cells and the operation is done on the particles in each cell. The spatial field $\bar\phi$ is calculated based on the following equation (number-based):

$$ \bar\phi _ { cell } = \frac {\sum \phi_{i}}{denominator}, \ i\in cell,\ and \ i\in mask $$

where denominator depends on the type of operation we are performing:

• If we are performing sum operation, $denominator = 1$
• If we are performing average operation, $denominator = \sum _ {i} 1,\ i\in cell$
• If we are performing averageMask operation, $denominator = \sum _ {i} 1, i\in cell$, and $i\in mask$

Problem definition

We are going to post-process the simulation results of the case rotating drum with binary particles. We calculate the spatial average velocity of particles and concentration (number-based) of small particles in the drum.

Post processing of the particle fields yields some new space-averaged fields

Note: the images are obtained from a similar case setup with higher number of particles.

---

Case setup