The Bubble number density, final result shows the density of bubbles through the part at the end of the analysis.
This result is generated from a Microcellular injection molding analysis, for the following mesh types:
If you selected the Constant Nucleation model, the bubble number density result will be uniform throughout the part and will reflect the value you entered in the Process Settings dialog, under Number of cells per volume.
If you selected the Fitted Classical Bubble Nucleation model, this model predicts the number of bubbles in any area of the part at the end of the analysis, and depends on the nature and volume of the foaming gas, the polymer properties, the local temperature, and the pressure.
Ideally, the bubble number density should be fairly uniform throughout the core regions of the part. An area with very few bubbles may indicate that there is insufficient foaming (SFC) gas present, or that the part froze early before the pressure decreased sufficiently to allow bubble growth.
You may want to study the bubble size result and the bubble number density result, in conjunction with this result.