THE SIMULATION OF GRANULAR PARTICLE ON DRY AND MOISTURIZED POROUS HORIZONTAL SURFACES

Simulations were carried out to visualize the ratio of granular attachment to porous surfaces. This simulation uses a uFlex three-dimensional simulation using three sizes of porous surface systems in the condition of the smallest human pores and the most extensive human pores and the condition of wet skin and dry skin. Each system was tested using five granular particle sizes according to the range of the makeup granules’ size to determine the optimal adhesive. The results show that the number of cosmetic granular particles entering the porous surface system is directly proportional to the porous surface volume and moisture and inversely proportional to the granular cosmetic size. The larger the cosmetic granular used, the less granular enters the pore.

Structure and compressive behavior of Lightweight Clay Aggregate particle: experiments and numerical simulations

Lightweight Clay Aggregate (LWCA) is a kind of highly porous granular particle which is often used as lightweight backfilling geomaterials. However, the easy breakage of LWCA particle plays a negative role in its geotechnical application. This study focuses on the internal structure and compressive behavior of single LWCA particle using experiments and numerical simulations. The uniaxial compressive strength and loading stiffness of the LWCA particle is attributed to its special porous internal structure. The results could enrich our understanding in particle crushing.

Strain localization and failure of disordered particle rafts with tunable ductility during tensile deformation

Tensile experiments of disordered granular particle rafts at an air–oil interface show that their ductility can be tuned by the particle size.

Experimental study of granular bed erosion and sedimentation subjugated to the secondary flow structures in curved ducts

This article presents an experimental study on the dynamic behaviour of granular material that forms the bed of a curved fluid flow passage. The secondary vortex structures induced by the passage curvature profoundly influence the stability of the granular material and determine the varying bed profiles subjected to the processes of erosion and sedimentation in the flow passage. For examining the characteristics of the bed profile, the current study develops a non-intrusive measurement method whereby transient changes occurring at the granular bed interface are captured for a range of flow operating conditions. The test results indicate three distinct regimes of onset, transition and quasi-stable erosion–sedimentation in the curved passage over the experimental test range. Each stage is analysed and discussed for the observed intricacies of the flow structures and the bed reshaping behaviour, with respect to the timescale of these occurrences, influences of the flow rate and granular particle size.

Gravitational instabilities in binary granular materials

The motion and mixing of granular media are observed in several contexts in nature, often displaying striking similarities to liquids. Granular dynamics occur in geological phenomena and also enable technologies ranging from pharmaceuticals production to carbon capture. Here, we report the discovery of a family of gravitational instabilities in granular particle mixtures subject to vertical vibration and upward gas flow, including a Rayleigh–Taylor (RT)-like instability in which lighter grains rise through heavier grains in the form of “fingers” and “granular bubbles.” We demonstrate that this RT-like instability arises due to a competition between upward drag force increased locally by gas channeling and downward contact forces, and thus the physical mechanism is entirely different from that found in liquids. This gas channeling mechanism also generates other gravitational instabilities: the rise of a granular bubble which leaves a trail of particles behind it and the cascading branching of a descending granular droplet. These instabilities suggest opportunities for patterning within granular mixtures.