Ballistic agglomeration

The propellant grains will agglomerate whereby ignition will suffer. The same disadvantage may be caused by crystalline separation of stabilizers. The ballistic performance can also be affected. 

In ballistic collision processes, the mean free path of the colliding objects is large compared with their size their motion can be represented by linear trajectories instead of the random walk used in DLA. Primary particles colliding with a fixed agglomerate penetrate more deeply into the interior of the agglomerate than in DLA and produce very compact structures... 

Ballistic aggregation (Figure 7.10c). This is similar to DLA but the incoming monomers that are trapped by the cluster do not follow a Brownian path but straight lines. The agglomerate that results is a bit more porous than in the case of RLA but it is not fractal the dimension of the cluster is d (3 in space and 2 on a flat screen). 

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