GEOMETRICAL PROPERTIES OF AGGREGATES WITH TUNABLE FRACTAL DIMENSION

We have computed geometrical characteristics of large clusters (up to 32 768 particles) obtained by a hierarchical cluster-cluster aggregati on computer model in three dimensions, the off-lattice variable-D mode l. Using a 'box-counting' method, we have calculated the fractal dimen sions of the surface D-s and the perimeter D-p of their two-dimensiona l projections as a function of their fractal dimension D. By diagonali zing the radius of gyration tensor, we have obtained numerical estimat es for the intrinsic anisotropy coefficients (ratios of the eigenvalue s) and we have proposed analytical expressions to describe their behav iour as a function of the fractal dimension.