The influence of particle size distribution on parameters characterizing the spatial structure of porous beds

The article proposes functions linking the standard deviation of a particle distribution in a porous bed consisting of spherical particles with various parameters characterising the spatial structure of the bed. The porosity, the inner surface, the specific surface and the geometrical tortuosity were analysed. In the first stage, a set of virtual beds was created with the use of the Discrete Element Method. The Radius Expansion Method was applied to generate virtual beds with different standard deviations. 150 virtual beds were created (25 standard deviations, 3 repetitions with different settings of the random number generator, 2 values of the radius expansion factor). In the second stage, the spatial structure of all virtual beds was analysed. The geometrical tortuosity was calculated with the use of the so-called Path Tracking Method; other parameters were calculated with the use of analytical formulas. The impact of the standard deviation on the parameters characterising the spatial structure of the granular bed was described by approximation functions, which can be used in order to obtain these parameters based on the particle size distribution for others porous beds.