ROS-management in Parkinson’s disease: Dynamic blue-print domino-based model and design principles study. Dynamic modelling of ROS management and ROS-induced mitophagy

Poster (2014, October)

Decentralized Power Supply for Small and Medium User Facilities

Patent (2014)

The world-wide energy consumption has almost doubled since 1980 despite efforts towards energy saving and efficiency. This trend is supposed to continue for the decades to come so that major energy crises ... [more ▼]

The world-wide energy consumption has almost doubled since 1980 despite efforts towards energy saving and efficiency. This trend is supposed to continue for the decades to come so that major energy crises with electricity cuts and shortage of petrol or gas are anticipated. Furthermore, an ever increasing consumption of fossil fuels significantly contributes to further emissions of greenhouse gases and consequently to global warming in conjunction with catastrophic climate changes. These impacts are reduced to a large extent through utilisation of renewable energy sources for and within decentralised user facilities. The present invention relates to a method of communicating operation modes between a user facility control unit at a user facility and a utility grid control unit of a utility grid. In particular, it relates to a decentralised method of communicating operation modes between a user facility control unit at a user facility with renewable energy supply and a utility grid control unit of a utility grid. [less ▲]

Dynamic modelling of ROS management and ROS-induced mitophagy

Poster (2014, June)

eXtended Discrete Element Method used for predicting tungsten-oxide reduction in a dry-hydrogen atmosphere

in LLanes, Luis (Ed.) eXtended Discrete Element Method used for predicting tungsten-oxide reduction in a dry-hydrogen atmosphere (2014, March 10)

Application of XDEM as a novel approach to predict drying of a packed bed

in International Journal of Thermal Sciences (2014), 75

A majority of solid fuels especially biomass contains moisture, which may amount up to the mass of the dry particles. Thus it is important to determine the details of drying when considering biomass as a ... [more ▼]

A majority of solid fuels especially biomass contains moisture, which may amount up to the mass of the dry particles. Thus it is important to determine the details of drying when considering biomass as a fuel. Therefore, the objective of this work is to apply the Extended Discrete Element Method (XDEM) as a numerical simulation framework to prediction of drying within a packed bed reactor. The novel numerical concept resolves the particulate phase by the classical Discrete Element Method (DEM), however, extends it by the thermodynamic state e.g. temperature distribution and evaporation of water content of each particle in conjunction with heat and mass transfer to the surrounding gas phase. The latter is described by a continuous approach namely a set of differential conservation equations as employed in Computational Fluid Dynamics (CFD) for porous media. Comparison with measurement was carried out and good agreement was achieved. [less ▲]

The extended discrete element method (XDEM) applied to drying of a packed bed

in Industrial Combustion (2014), 14

A vast number of engineering applications involve physics not solely of a single domain but of several physical phenomena, and therefore are referred to as multi-physical. As long as the phenomena ... [more ▼]

A vast number of engineering applications involve physics not solely of a single domain but of several physical phenomena, and therefore are referred to as multi-physical. As long as the phenomena considered are to be treated by either a continuous (i.e. Eulerian) or discrete (i.e. Lagrangian) approach, numerical solution methods may be employed to solve the problem. However, numerous challenges in engineering exist and evolve; those include modelling a continuous and discrete phase simultaneously, which cannot be solved accurately by continuous or discrete approaches only. Problems that involve both a continuous and a discrete phase are important in applications as diverse as the pharmaceutical industry, the food processing industry, mining, construction, agricultural machinery, metals manufacturing, energy production and systems biology. A novel technique referred to as Extended Discrete Element Method (XDEM) has been developed that offers a significant advancement for coupled discrete and continuous numerical simulation concepts. XDEM extends the dynamics of granular materials or particles as described through the classical discrete element method (DEM) to include additional properties such as the thermodynamic state or stress/strain for each particle coupled to a continuous phase such as a fluid flow or a solid structure. Contrary to a continuum mechanics concept, XDEM aims at resolving the particulate phase through the various processes attached to particles. While DEM predicts the spatial-temporal position and orientation for each particle, XDEM additionally estimates properties such as the internal temperature and/or species distribution during drying, pyrolysis or combustion of solid fuel material such as biomass in a packed bed. These predictive capabilities are further extended by an interaction with fluid flow by heat, mass and momentum transfer and the impact of particles on structures. © International Flame Research Foundation, 2014. [less ▲]

XDEM - FEM Coupling Simulations of the Interactions between a Tire Tread and Granular Terrain

E-print/Working paper (2014)

This study proposes an efficient combination of the Discrete Element Method (DEM) and the Finite Element Method (FEM) to study the tractive performance of a rubber tire in interaction with granular ... [more ▼]

This study proposes an efficient combination of the Discrete Element Method (DEM) and the Finite Element Method (FEM) to study the tractive performance of a rubber tire in interaction with granular terrain. The presented approach is relevant to all engineering devices interacting with granular matter which causes response forces. Herein, the extended discrete element method (XDEM) is used to describe the dynamics of the granular assembly. On the one hand, the discrete approach accounts for the motion and forces of each grain individually. On the other hand, the finite element method accurately predicts the deformations and stresses acting within the tire tread. Hence, the simulation domain occupied by the tire tread is efficiently described as a continuous entity. The coupling of both methods is based on the interface shared by the two spatially separated domains. Contact forces develop at the interface and propagate into each domain. The coupling method enables to capture both responses simultaneously and allows to sufficiently resolve the different length scales. Each grain in contact with the surface of the tire tread generates a contact force which it reacts on repulsively. The contact forces sum up over the tread surface and cause the tire tread to deform. The coupling method compensates quite naturally the shortages of both numerical methods. It further employs a fast contact detection algorithm to save valuable computation time. The proposed DEM-FEM Coupling technique was employed to study the tractive performance of a rubber tire with lug tread patterns in a soil bed. The contact forces at the tread surface are captured by 3D simulations for a tire slip of 5%. The simulations showed to accurately recapture the gross tractive effort, running resistance and drawbar pull of the tire tread in comparison to related measurements. Further, the traction mechanisms between the tire tread and the granular ground are studied by analysing the motion of the soil grains and the deformation of the tread. [less ▲]

Experimental and Numerical Evaluation of the Residence Time Characteristics on a Forward Acting Grate

in Condensed Matter 2014 (2014)

Transport Characteristics of Granular Matter on a Forward Acting Grate

in COST Action MP1305 Flowing Matter (2014)

An Efficient 3D FEM - DEM Coupling for Granular Matter Applications

in Coupled MBS-FE Applications: A New Trend in Simulation (2013, November)

The presented approach is relevant to almost all engineering applications that deal with granular matter such as off-road tire performance, transport on conveyor belts or displacement of granular material ... [more ▼]

The presented approach is relevant to almost all engineering applications that deal with granular matter such as off-road tire performance, transport on conveyor belts or displacement of granular material as in mixers or excavation of soil. For all these applications an engineering device is in contact with granular matter which causes responses due to the interaction forces. The proposed Extended Discrete Element Method (XDEM) as a combination of the Discrete Element Method (DEM) and the Finite Element Method (FEM) allows to sufficiently resolve the different domains involved in these engineering applications. Herein the motion of each grain is accounted for individually. Simultaneously, the finite element method accurately predicts the deformations experienced by the engineering device. Thus, the simulation domain occupied by the device is efficiently described as a continuous entity. The coupling of both methods is based on the interface shared by the two spatially separated domains. The interface coupling enables to apply a contact model suited to the particular contact behaviour between the grains and the surface material if the engineering device. In contact, forces develop at the interface and generate an responce in each domain. The coupling method enables to capture both responses simultaneously. Each grain in contact with the device surface generates a contact force to which it reacts repulsively. The contact forces sum up over the surface and cause deformations of device body. It further employs a fast contact detection algorithm to save valuable computation time. This concept is supported by the software tools of the Discrete Particle Method (DPM) and Diffpack. To exemplify the presented method, the tractive performance of different tire treads has been studied on a soil layer of the stony terrian. The simulation results are used to analyse the gross tractive effort, running resistance and drawbar pull of the different tread patterns. [less ▲]