Mass transport in composite materials is affected by the properties of the constituent phases and their interfaces. This paper presents a discrete (lattice) model for simulating mass transport within multiphase materials. The lattice is based on Delaunay/Voronoi tessellations of a semi-random set of points. Fundamental properties of the lattice network are validated for potential flow through homogeneous media. Thereafter, flow is simulated through multiphase particulate materials, in which the inclusions have simple geometries. Explicit representation of the matrix-inclusion interphase enables precise control of interphase thickness and the simulation of percolation phenomena. As expected, interphase percolation leads to dramatic increases in effective permeability of the medium. The ability to calculate nodal flux, and from it visualize complex flow fields, is essential for model validation and model-based engineering of multiphase materials.

Flow field calculations within discrete models of multiphase materials

This paper presents the results of a study of the prediction of the entropy growth within an internal free shear layer of an ideal gas flow downstream of a sudden expansion of the flow area. The objective of the study is exploratory in nature by invoking concepts from information theory to connect the deterministic prediction of the spectral entropy growth within the shear layer to the experimentally inferred increase in entropy across the flow region. The deterministic prediction of the spectral entropy increase along the shear layer is brought into agreement with the experimentally inferred increase in entropy through the ad hoc inclusion of the activation spectral entropy. The values for this activation spectral entropy are directly related to the area ratios across the expansion region and have a specific numerical value for each area ratio.

https://www.mdpi.com/1099-4300/13/2/402/pdf

R.A. Adey

Papers

Potential flows — Computer graphics solutions