Distinctive sedimentary processes on two contrasting tidal flats of the Yellow River Delta

Coastal tidal flats provide valuable ecosystems, but are highly sensitive to tidal dynamics, sea-level rise, and human activities. Tidal inundation depth and frequency are known to affect tidal flat morphodynamics. However, the causes, processes and extent remain uncertain, particularly given the associated changes in sediment availability. In...

Finding Dangerous Waves-Review of Methods to Obtain Wave Impact Design Loads for Marine Structures

Green water and slamming wave impacts can lead to severe damage or operability issues for marine structures. It is therefore essential to consider their probability and loads in design. This is difficult, as impacts are both hydrodynamically complex and relatively rare. The complexity requires high-fidelity modeling (experiments or CFD),...

Sediment Pathways on Ebb-Tidal Deltas: New Tools and Techniques for Analysis

In an era of rising seas and other challenges posed by climate change, coastal regions like the Netherlands are facing ever graver threats. Strategic sand nourishments could mitigate the threat of coastal erosion and sea level rise on barrier island coasts while limiting ecological impacts. However, insufficient knowledge of sediment transport...

Lateral Flows and Sediment Dynamics in a Large Engineered Estuary

Estuaries are partially enclosed water bodies where river water mixes with sea water. Estuaries provide important ecological functions which are strongly regulated by estuarine hydrodynamics and sediment dynamics, and also by human interventions. Sustainable management of such systems therefore requires a thorough understanding of the interplay...

Computational fluid dynamics of gassed-stirred fermenters

The current understanding of the transport phenomena involved in the operation of industrial fermenters is not sufficient. This is reflected by the limitations seen in their design and operation. A better insight in the local processes taking place (hydrodynamics, gas dispersion, mixing, microbial kinetics) is required to be able to make a step...

Hydrodynamics of wind-assisted ship propulsion validation of RANS-CFD methodology

A Reynolds-Averaged Navier Stokes computational fluid dynamics (RANS-CFD) package will be one of the primary tools used during the development of a performance prediction program for Wind-Assisted commercial ships. The modelling challenge presented by large separated flow structures in the wake of the sailing ship points to a conscientious...

Application of neuro-fuzzy algorithm to portable dynamic positioning control system for ships

On the levitation force in horizontal core-annular flow with a large viscosity ratio and small density ratio

A numerical study has been made of horizontal core-annular flow: the flow of a high-viscosity liquid core surrounded by a low-viscosity liquid annular layer through a horizontal pipe. Special attention is paid to the question how the buoyancy force on the core, caused by a density difference between the core and the annular layer, is...

Hydrodynamics of a Monolithic Stirrer Reactor

The Monolithic Stirrer Reactor (MSR) is a novel concept for heterogeneously catalyzed reactors and is presented as an alternative device to slurry reactors. It uses a modified stirrer on which structured catalyst supports (monoliths) are fixed to form permeable blades. The monoliths consist of small square parallel channels on which a layer of...

Modeling of Ship Roll Dynamics and Its Coupling with Heave and Pitch

Dynamic Stability - Probabilistic Approaches

An experimental and numerical study on jack-up dynamic behavior

This paper presents the more salient results of an experimental and numerical study on jack-up dynamic behavior. The laboratory studies of three principle jack-up platform models were carried out in both regular and irregular waves. The data from irregular wave tests were analyzed in both the probability domain and frequency domain supported by...

On wings and keels

A discussion is given of the physical mechanisms governing the hydrodynamics of sailing yacht keels and the parameters that, through these mechanisms, determine keel performance. It is concluded that due to the presence of the free water surface optimum keel shapes differ from optimum shapes for aircraft wings, a fact that does not seem to have...

An unified dynamical analysis of anti-symmetric ship response to waves