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Stability of dusty rings in protoplanetary discs

Chan, Kevin (author), Paardekooper, S. (author)

Dust rings in protoplanetary discs are often observed in thermal dust emission and could be fa v ourable environments for planet formation. While dust rings readily form in gas pressure maxima, their long-term stability is key to both their observability and potential to assist in planet formation. We investigate the stability of the dust...

journal article 2024

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Migration of low-mass planets in inviscid discs: the effect of radiation transport on the dynamical corotation torque

Ziampras, Alexandros (author), Nelson, Richard P. (author), Paardekooper, S. (author)

Low-mass planets migrate in the type-I regime. In the inviscid limit, the contrast between the vortensity trapped inside the planet's corotating region and the background disc vortensity leads to a dynamical corotation torque, which is thought to slow down inward migration. We investigate the effect of radiative cooling on low-mass planet...

journal article 2024

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

Xie, Weiming (author), Sun, J. (author), Guo, Leicheng (author), Xu, Fan (author), Wang, Xianye (author), Ji, Hongyu (author), Fan, Yaoshen (author), Wang, Zhengbing (author), He, Qing (author)

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...

journal article 2023

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

van Essen, S.M. (author), Seyffert, Harleigh C. (author)

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),...

journal article 2023

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Peak Water Levels Rise Less Than Mean Sea Level in Tidal Channels Subject to Depth Convergence by Deepening

Leuven, Jasper R.F.W. (author), Niesten, Iris (author), Huismans, Y. (author), Cox, Jana R. (author), Hulsen, Lamber (author), van der Kaaij, Theo (author), Hoitink, A. J.F. (Ton) (author)

Effects of sea-level rise (SLR) on future peak water levels in tidal deltas and estuaries are largely unknown, despite these areas being densely populated and at high risk of flooding. While the rates of SLR accelerate, many channels simultaneously experience channel deepening for navigation. With globally decreasing sediment supplies, most...

journal article 2023

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Buoyancy response of a disc to an embedded planet: a cross-code comparison at high resolution

Ziampras, Alexandros (author), Paardekooper, S. (author), Nelson, Richard P. (author)

In radiatively inefficient, laminar protoplanetary discs, embedded planets can excite a buoyancy response as gas gets deflected vertically near the planet. This results in vertical oscillations that drive a vortensity growth in the planet's corotating region, speeding up inward migration in the type-I regime. We present a comparison between...

journal article 2023

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Simulation of Groundwater Flow Dynamics under Different Stresses Using MODFLOW in Rechna Doab, Pakistan

Awais, Muhammad (author), Arshad, Muhammad (author), Ahmad, Sajid Rashid (author), Nazeer, A. (author), Waqas, Muhammad Mohsin (author), Aziz, Rizwan (author), Shakoor, Aamir (author), Rizwan, Muhammad (author), Chauhdary, Junaid Nawaz (author)

Groundwater is a primary source of freshwater provisions all around the world. Due to its limited availability, water has become a precious entity nowadays. The future accessibility of groundwater is endangered due to its massive exploitation, particularly in the irrigation sector. Therefore, the current study was conducted to assess the...

journal article 2022

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The Impact of the Spectral Tail on the Evolution of the Kurtosis of Random Seas

Barratt, Dylan (author), van den Bremer, T.S. (author), Adcock, Thomas A.A. (author)

We perform simulations of random seas based on narrow-banded spectra with directional spreading. Our wavefields are spatially homogeneous and nonstationary in time. We truncate the spectral tail for the initial conditions at different cutoff wavenumbers to assess the impact of the spectral tail on the kurtosis and spectral evolution. We...

journal article 2022

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Impact of Coral Reef Mining Pits on Nearshore Hydrodynamics and Wave Runup During Extreme Wave Events

Klaver, S. (author), Nederhoff, C. M. (author), Giardino, A. (author), Tissier, M.F.S. (author), van Dongeren, A. R. (author), van der Spek, A.J.F. (author)

Small island developing states are among the most vulnerable areas to the impact of natural hazards and climate change. Flooding due to storm surges and extreme waves, coastal erosion, and salinization of freshwater lenses are already a serious threat and could lead to irreversible consequences in the coming decades. Reef flat mining is one...

journal article 2019

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The Importance of Combined Tidal and Meteorological Forces for the Flow and Sediment Transport on Intertidal Shoals

de Vet, P.L.M. (author), van Prooijen, Bram (author), Schrijvershof, R. A. (author), van der Werf, J. J. (author), Ysebaert, T. (author), Schrijver, M. C. (author), Wang, Zhengbing (author)

Estuarine intertidal areas are shaped by combined astronomical and meteorological forces. This paper reveals the relative importance of tide, surge, wind, and waves for the flow and sediment transport on large intertidal shoals. Results of an intensive field campaign have been used to validate a numerical model of the Roggenplaat intertidal...

journal article 2018

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A Bayesian-Based System to Assess Wave-Driven Flooding Hazards on Coral Reef-Lined Coasts

Pearson, S.G. (author), Storlazzi, C.D. (author), van Dongeren, A. R. (author), Tissier, M.F.S. (author), Reniers, A.J.H.M. (author)

Many low-elevation, coral reef-lined, tropical coasts are vulnerable to the effects of climate change, sea level rise, and wave-induced flooding. The considerable morphological diversity of these coasts and the variability of the hydrodynamic forcing that they are exposed to make predicting wave-induced flooding a challenge. A process-based...

journal article 2017

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Onsager’s reciprocal relations in electrolyte solutions: II. Effect of ionic interactions on electroacoustic

Gourdin-Bertin, S. (author), Chassagne, C. (author), Bernard, O. (author), Jardat, M. (author)

In electrolyte solutions, an electric potential difference, called the Ionic Vibration Potential (IVP), related to the ionic vibration intensity, is generated by the application of an acoustic wave. Several theories based on a mechanical framework have been proposed over the years to predict the IVP for high ionic strengths, in the case where...

journal article 2015

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Accurate vertical profiles of turbulent flow in z-layer models

Platzek, F.W. (author), Stelling, G.S. (author), Jankowski, J.A. (author), Pietrzak, J.D. (author)

Three-dimensional hydrodynamic z-layer models, which are used for simulating the flow in rivers, estuaries, and oceans, suffer from an inaccurate and often discontinuous bottom shear stress representation, due to the staircase bottom. We analyze the governing equations and clearly show the cause of the inaccuracies. Based on the analysis, we...

journal article 2014

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Numerical modelling of finite-size particle collisions in a viscous fluid

Brändle de Motta, J.C. (author), Breugem, W.P. (author), Gazanion, B. (author), Estivalezes, J.L. (author), Vincent, S. (author), Climent, E. (author)

A general model is presented for short-range hydrodynamic interactions and head-on particle-particle/wall collisions. The model has been embedded in two distinct numerical methods for fully resolved simulation of finite-size particles in a viscous fluid. It accounts for the material properties of the particles and lubrication effects prior to...

journal article 2013

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

Ooms, G. (author), Pourquie, M.J.B.M. (author), Beerens, J.C. (author)

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...

journal article 2013

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Rowing faster by surface treatment

Greidanus, A.J. (author), Delfos, R. (author), Westerweel, J. (author)

The largest part of hydrodynamic drag during rowing, sailing or canoeing is the turbulent skin friction (80-90%). Higher velocities can be achieved by reducing the friction drag as a result of surface treatment. This research focuses on the development, characterization, and testing of drag-reducing surfaces, like nano- and micro-structured...

journal article 2012

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Efficient scheme for the shallow water equations on unstructured grids with application to the Continental Shelf

Kernkamp, H.W.J. (author), Van Dam, A. (author), Stelling, G.S. (author), De Goede, E.D. (author)

In this paper, a shallow-water flow solver is presented, based on the finite-volume method on unstructured grids The method is suitable for flows that occur in rivers, channels, sewer systems (1D), shallow seas, rivers, overland flow (2D), and estuaries, lakes and shelf breaks (3D). We present an outline of the numerical approach and show three...

journal article 2011

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Hydrodynamic processes in sharp meander bends and their morphological implications

Blanckaert, K. (author)

The migration rate of sharp meander bends exhibits large variance and indicates that some sharply curved bends tend to stabilize. These observations remain unexplained. This paper examines three hydrodynamic processes in sharp bends with fixed banks and discusses their morphological implications: secondary flow saturation, outer-banks cells, and...

journal article 2011

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Meander dynamics: A nonlinear model without curvature restrictions for flow in open?channel bends

Blanckaert, K. (author), De Vriend, H.J. (author)

Despite the rapid evolution of computational power, simulation of meander dynamics by means of reduced and computationally less expensive models remains practically relevant for investigation of large?scale and long?term processes, probabilistic predictions, or rapid assessments. Existing meander models are invariantly based on the assumptions...

journal article 2010

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Development of an innovative single scull for the recreational rower

Voogd-Claessen, H. (author), Van Bladel, C. (author), Van Daalen, T. (author), Dekkers, B. (author), Elwick, R. (author), Mulder, F. (author), Nachmany, G. (author)

Rowing is a sport which requires a proper technique, strong core balance, physical strength and endurance. Rowing boats designed for competition are built of epoxy laminate with glass or carbon reinforcement; they are lightweight, stiff, long, and narrow to achieve minimal water resistance. However, this makes them extremely unstable and...

journal article 2010