Final Report: Computational Study of Colloidal Droplet Interactions with Three Dimensional Structures

Number of Papers published in peer-reviewed journals: Number of Papers published in non peer-reviewed journals: Final Report: Computational Study of Colloidal Droplet Interactions with Three Dimensional Structures Report Title The colloidal droplet spreading on and sorption into a porous medium is important to 3D printing technology. In this study, we conducted numerical simulation to investigate droplet spreading on and sorption into a powder bed and performed experiment to study the colloidal fluid distribution in the porous structure after sorption of single/multiple droplets in powder beds. The spreading of the droplet on the surface of the porous matrix is modeled based on the Navier-Stokes equation while the liquid sorption in the porous matrix is described using the Brinkman-Forchheimer-Darcy equation. The interaction between the nanoparticle and the solid matrix is modeled using a particle trajectory method. Using the multi-scale modeling approach, a parametric study was conducted to investigate the effects of the droplet impact speed, the fluid viscosity, and the permeability of the porous matrix on the spreading diameter. We also use microCT imaging method to investigate the distribution of the colloidal fluid in the PMMA powder bed after absorption of ferrofluid droplets. (a) Papers published in peer-reviewed journals (N/A for none) Enter List of papers submitted or published that acknowledge ARO support from the start of the project to the date of this printing. List the papers, including journal references, in the following categories: (b) Papers published in non-peer-reviewed journals (N/A for none) (c) Presentations Received Paper