A discrete numerical model of the front region in piping erosion: (Abstract)

Surface wear reduction of bulk solids handling equipment using bionic design

Bulk solids handling continues to play an important role in a number of industries. One of the issues during bulk solids handling processes is equipment surface wear. Wear results in high economic loss and increases downtime. Current wear reduction methods such as optimizing transfer conditions or using wear-resistant materials, have brought...

Excavation of hard deposits and rocks: On the cutting of saturated rock

As a result of the worldwide population and welfare growth, the demand for energy (oil, gas and renewable sources) and raw materials increases. In the last decades, oil and gas are produced from more and more offshore sites and deeper waters. Besides energy, the demand for diverse metals and rare earth elements increases as well. These raw...

Improving the chute design for Eurosilo system

The transfer chute design for Eurosilo system handling coal was found to fail due to wear. The current transfer chute was designed based on rockbox concept. There are no specific methodologies for design of chutes for a rock box concept involving a very high velocity transfer. New or improved designs were required to sustain in the industry. The...

Virtual prototyping of grabs: Co-simulations of discrete element and rigid body models

This dissertation has investigated whether a combination of DEM and MBD can be used for a reliable and accurate environment for predicting grab unloading performance. A grab is a type of bulk material handling equipment used for unloading materials such as coal and iron ore from vessel to shore. Both a grab and iron ore pellets have been...

Modelling dust liberation in bulk material handling systems

Dust has negative effects on the environmental conditions, human health as well as industrial equipment and processes. In this thesis, the transfer point of a belt conveyor as a bulk material handling system with a very high potential place for dust liberation is studied. This study is conducted based on experimental and numerical methods as...

Dynamics of Flexible Risers for Deep Sea Mining Applications

The objective of this thesis is to develop a numerical model, which could be used to predict the deflections and stresses in the flexible risers during one operation cycle. The numerical model of the flexible risers is mainly developed based on Timoshenko Beam Theory and Discrete Element Method. The internal slurry flow is simulated as plug flow...

On the durability tests for handling of solid biomass such as wood pellets

Modelling Single Particle Settlement by CFD-DEM Coupling Method

Dust liberation (a gas-solid two phase problem) is a highly complicated phenomenon to be studied due to great number of variables to be considered, so any related theoretical or numerical simulation is forced to implement many simplifications. Furthermore, there are numerous methods to study such a problem one of them is the newly introduced CFD...

DEM speedup: Stiffness effects on behavior of bulk material

Numerical modelling of forces, stresses and breakages of concrete armour units

Numerical modelling has the potential to probe the complexity of the interacting physics of rubble mound armour systems. Through forward modelling of armour unit packs, stochastic variables such as unit displacement and maximum contact force per unit during an external oscillatory disturbance can be predicted. The combined finite-discrete...

Simulation of macroscopic behavior of a self-compacting mixture based on DEM

Since the early 20th century, the necessity of modeling and monitoring fresh concrete behavior has been recognized by the industry with the objective to ensure adequate mechanical properties and a proper durability of concrete structures. Due to the rapid development of computer technology, the applications of computational simulation tools in...

Dust Emission Modeling around a Stockpile by Using Computational Fluid Dynamics and Discrete Element Method

Modelling of material flow and size distribution of ore in a stockpile at Tara Mines, Ireland

This study aims to understand the material behaviour of ore inside a coarse ore stockpile by discrete element modelling. This is of importance since the stockpile is the last stage to control the size distribution of ore in the ore handling system before feeding the grinding circuit. An optimal size distribution is required for efficient...

Brazil Nut Effect and CONCRETE: Entering Terra Incognita

This paper presents some evidence of the impact of the Brazil nut effect (BNE) on concrete’s particulate structure on meso-level (aggregate) as well as on micro-level (cement paste). BNE is associated with long-range size segregation in particle mixtures due to vibration in slurry state of concrete, both near boundaries and in bulk. Presented...

Particulate structure and microstructure evolution of concrete investigated by DEM: Part 1: Aggregate and binder packing

Experimental approaches in concrete technology are time-consuming, laborious and thus expensive. Developments in computer facilities render possible nowadays realistically simulating the particulate structure and microstructure of cementitious materials. For that purpose, discrete element methods (DEM) are required because of more correctly...

Mechanics of Granular Materials: Constitutive Behavior and Pattern Transformation

From pharmaceutical to mining or traveling desert dunes to earthquakes, granular materials are at the heart of many industries and natural phenomena. Improving the efficiency of the machines handling them or, constructing safer buildings requires a critical understanding of their behavior. However, this is not a straightforward task as opposed...

The pentration of iron ore pellets: calibrating descrete element parameters using penetration tests