Turbulent Winds and Temperature Fronts in Large-Eddy Simulations of the Stable Atmospheric Boundary Layer

The impact of shallow cover on tunnelling in soft soil

Stability and robustness analysis of acyclic timetable

To satisfy the growing passenger transportation demands and improve the service quality n railway system, a more stable and robust timetable needs to be designed while considering highly utilized capacity. Acyclic timetable is extensively applied in large ailway networks. In order to acquire the quality of timetable, analytical timetable...

A three-level framework for performance-based railway timetabling

The performance of railway operations depends highly on the quality of the railway timetable. In particular for dense railway networks it can be a challenge to obtain a stable robust conflict-free and energy-efficient timetable with acceptable infrastructure occupation and short travel times. This paper presents a performance-based railway...

Validation and Optimization of a Design Formula for Stable Geometrically Open Filter Structures

Granular filters are used for protection against scour and erosion of base material. For a proper functioning it is necessary that at the interfaces between the filter structure, the subsoil and the water flowing above the filter structure no material will be transported. Different types of granular filters can be distinguished, this paper...

Detrainment in deep convection

This study explores the mechanisms that determine detrainment in deep cumulus convection. A set of 90 high-resolution Large Eddy Simulations is used to systematically explore the sensitivity of continental deep convection to the relative humidity and stability of the free troposphere. It appears that variations in the mass-flux profiles are...

Stable and unstable coastal inlet cross-sectional behaviour

A review will be presented of the theory behind stable and unstable coastal inlet cross-sectional behaviour. The theoretical findings behind stable coastal inlet cross-sectional behaviour will be reviewed, analysed and confronted with empirical findings, leading to some unresolved questions. Second, seasonal variations will be shown to induce...

On the time-stepping stability of continuous mass-lumped and discontinuous Galerkin finite elements for the 3D acoustic wave equation

We solve the three-dimensional acoustic wave equation, discretized on tetrahedral meshes. Two methods are considered: mass-lumped continuous finite elements and the symmetric interior-penalty discontinuous Galerkin method (SIP-DG). Combining the spatial discretization with the leap-frog time-stepping scheme, which is second-order accurate and...

Bifurcation dynamics and avulsion duration in meandering rivers by one-dimensional and three-dimensional models

At river bifurcations, water and sediment are divided over two branches. The dynamics of the bifurcation determine the long-term evolution (centuries) of the downstream branches, potentially leading to avulsion, but the dynamics are poorly understood. The long-term evolution can only be studied by one-dimensional models because of computational...

Report on measurements: Pressure and velocity fluctuations around a granular-bed element

The second chapter describes the general methodology of the research. It presents the key questions about the entrainment of stones from granular filters that are as yet unanswered. It also describes the aspects that are being regarded in the analysis in this report. In chapter 3 the measuring set-up is described. The following two chapters...

Bowthrusters and the stability of a riprap revetment

Because of problems with the design guidelines produced by PIANC for armoured slopes under attack by bowthrusters, additional work has been done in the Netherlands. On the basis of this work computational rules have been developed. However, because of the increase of bowthruster power, more detailed knowledge is needed on the effect of a...

Pressure Sensors and Filtering Techniques for Stone Stability Assessment

This report is structured as follows: In chapter 2 the importance of wall pressures with respect to the present research is described. The literature on wall pressures that was used, and some general features of wall pressure fluctuations are subsequently described in chapter 3. Chapter 4 deals with the pressure sensors. It begins with a brief...

Stability of stones in the top layer of a granular filter: Literature survey

In order to understand the processes involved in damaging a granular filter, the behaviour of the separate particles it is made of must be known. The hydrodynamic forces on the particles are very important for understanding this behaviour. These forces have been examined by many researchers. Chapter 2 deals with that aspect. The characteristics...