Particle dynamics in drying colloidal solution using discrete particle method

We study particle dynamics in drying colloidal solutions using the numerical simulation with discrete particle method (DPM). Simulations of two different systems were conducted; the drying dynamics of monodispersed and binary mixture of colloidal solution, and compared with those from the previous studies. In the monodispersed colloidal solution, the time evolution of particle concentration profile for varying Péclet number was simulated with the same initial particle concentration. In the binary colloidal solution, when the particle size ratio α is 3, three different stratification modes were observed varying Péclet number and initial particle concentration. By comparison, our method was in a good agreement with the existing methods. Additionally, because of the mesh-based Eulerian approach in our model, other various multi-physical phenomena, such as effect of thermal Marangoni or chemical reaction, can be included in an easy way. From the results, we expect that this work can provide a physical insight for predicting the quality of colloidal drying in a complicated situation.

Statistical Distributions of the Elastic Moduli of Particle Aggregates at the Mesoscale

The current work is part of an ongoing effort to couple the Discrete Element Method (DEM), used as a mesoscale method, with Statistical Mechanics in order to construct a framework for the modeling, homogenization, and uncertainty quantification of particulate geomaterials. The aspect of the framework tackled in this work, is the quantification of stress and deformation of heterogenous DE models. Such quantification is necessary to allow DEM to “speak continuum”. DEM is a discrete particle method, wherein the concept of “stress” does not fit naturally, but where each particle pair is considered to interact through discrete forces. Additionally, DEM is an explicit method, and equivalent continuum deformation must be defined in the context of particle kinematics.