Difference in Number of Particles Tracked in the DPM Histogram

Why is the Ansys Fluent DPM histogram showing a different number of particles than where tracked?

The DPM (Discrete Phase Model) histogram shows the number of particles only. However, Ansys Fluent uses parcels for tracking. Each parcel contains a number or particles that behave in the same way.

This concept also applies when using DEM (discrete element method) collisions.

If you want to track each particle, you can change the "Parcel Release Method" that you can find for each injection on the "Parcel" tab. This is only available for transient particle tracking.

Keep in mind that you might need a significantly smaller time step size and significantly more computational time when increasing the number of parcels.