Fractal analysis of aggregates: Correlation between the 2D and 3D box-counting fractal dimension and power law fractal dimension

Fractal dimension (Df) has been extensively used for many years to characterize the morphological properties of aggregate systems. There are two main methods to estimate the fractal dimension of aggregates, namely the box counting (BC) and power law (PL) methods. However, the relationship between the BC fractal dimension (Df, BC) and PL fractal dimension (Df, PL) has not been discussed yet. In this work, a series of three-dimensional aggregates with different input parameters (Df, PL and the number of primary particles) is generated by a tunable aggregation model. Then, the fractal dimensions (Df, BC, 3D) of all the aggregates are estimated by the 3D BC method. The relationship between Df, BC, 3D and Df, PL is investigated. We found that Df, BC, 3D is greater than Df, PL when Df, PL & LE; 2.5. However, the situation is reversed when Df, PL > 2.5. Further, a novel projection method is proposed and applied to all the 3D aggregates to obtain their 2D projection images. In this projection method, the minimum projection overlapping area of all the primary particles in the aggregate is considered. Then, the fractal dimensions (Df, BC, 2D) of 2D projection images are estimated using the 2D BC method. Finally, correlations between Df, BC, 3D and Df, PL with Df, BC, 2D are established. (c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

This study investigates the relationship between the box counting (BC) and power law (PL) methods for estimating the fractal dimension of aggregates. The results show that the BC fractal dimension is greater than the PL fractal dimension when the PL fractal dimension is less than or equal to 2.5, and vice versa when the PL fractal dimension is greater than 2.5. The study also proposes a projection method to obtain two-dimensional projection images of the aggregates and establishes correlations between the two-dimensional BC fractal dimension and the three-dimensional and PL fractal dimensions.