The axial segregation of granular and particulate media is a well-known but little-understood phenomenon with direct relevance to various natural and industrial processes. Over the past decades, many attempts have been made to understand this phenomenon, resulting in a significant number of proposed mechanisms, none of which can provide a full and universally applicable explanation. In this paper, we show that several mechanisms can be simultaneously active within a single system, and that by considering all relevant mechanisms, it is possible to understand and explain a system's segregative behaviours over a wider range of parameter space than is possible by considering any one, single process. We explore the interrelation and competition between the individual mechanisms present within a given system and demonstrate that by understanding these interactions, we can predict and even, through carefully designed systems, control their behaviour. In particular, we demonstrate that it is possible to deliberately direct segregation, allowing an arbitrary number of pre-determined segregation patterns to be induced in a system. We also illustrate a manner in which the competition between two opposing segregation mechanisms may be exploited in order to enhance the mixing of two dissimilar species of particle-a much sought after ability.

Fundamentals of nonlinear wave-particle interactions are studied experimentally in a Hele-Shaw configuration with wave breaking and a dynamic bed. To design this configuration, we determine, mathematically, the gap width which allows inertial flows to survive the viscous damping due to the side walls. Damped wave sloshing experiments compared with simulations confirm that width-averaged potential-flow models with linear momen- 2A n t h o n y T h o r n t o n e t a l .tum damping are adequately capturing the large scale nonlinear wave motion. Subsequently, we show that the four types of wave breaking observed at realworld beaches also emerge on Hele-Shaw laboratory beaches, albeit in idealized forms. Finally, an experimental parameter study is undertaken to quantify the formation of quasi-steady beach morphologies due to nonlinear, breaking waves: berm or dune, beach and bar formation are all classified. Our research reveals that the Hele-Shaw beach configuration allows a wealth of experimental and modelling extensions, including benchmarking of forecast models used in the coastal engineering practice, especially for shingle beaches.

MercuryDPM is an open-source particle simulation tool-fully written in C++-developed at the University of Twente. It contains a large range of contact models, allowing for simulations of complex interactions such as sintering, breaking, plastic deformation, wet-materials and cohesion, all of which have important industrial applications. The code also contains novel complex wall generation techniques, that can exactly model real industrial geometries. Additionally, MercuryDPMs' state-of-the-art built-in statistics package constructs accurate three-dimensional continuum fields such as density, velocity, structure and stress tensors, providing information often not available from scaled-down model experiments or pilot plants. The statistics package was initially developed to analyse granular mixtures flowing over inclined channels, and has since been extended to investigate several other granular applications. In this proceeding, we review these novel techniques, whereas its applications will be discussed in its sequel.

The primary evolution of beaches by wave action takes place during storms. Beach evolution by non-linear breaking waves is 3D, multi-scale, and involves particle-wave interactions. We will show how a novel, three-phase extension to the classic "Hele-Shaw" laboratory experiment is designed to create beach morphologies with breaking waves in a quasi-2D setting. Idealized beaches emerge in tens of minutes due to several types of breaking waves, with about 1s periods. The thin Hele-Shaw cell simplifies the inherent complexity of three-phase dynamics by reducing the turbulence. Given the interest in the Hele-Shaw table-top demonstrations at ICCE2014, we will also discuss how different versions of the Hele-Shaw cell have been constructed. Construction can be inexpensive thus yielding an accessible and flexible coastal engineering demonstration as well as research tool. Beach evolution is sufficiently fast and can start very far from equilibrium, allowing an unusually large dynamical range to be investigated.

We present evidence of axial banding in rotated, binary granular beds comprising particles of equal size but differing material density. It is demonstrated that the presence of differing particle densities alone may produce limited, localized axial segregation arising due to end-wall effects, but that true axial banding, i.e., axial segregation patterns pervading the full extent of the system may be induced through the use of a rotating tumbler whose internal geometry comprises alternating convex and concave segments. The segregation patterns formed are observed to be stable and reproducible, unlike the unpredictable, metastable banding typically observed in systems containing particles differing in size. Moreover, we demonstrate that, by varying the axial extent and positioning of the individual convex and concave segments, the system geometry may be deliberately tuned in order to directly control both the positions and the widths of the axial bands produced-a finding with significant potential benefits for a range of industrial processes.