- document
-
Lovato, S. (author), Toxopeus, S.L. (author), Settels, J.W. (author), Keetels, G.H. (author), Kirichek, Alex (author)The presence of mud layers on the bottom of ports and waterways can have negative effects on the hydrodynamic behaviour of marine vessels. This numerical study investigates the effect of muddy seabeds on the full-scale resistance of an oil tanker sailing straight ahead. The objective is to determine the influence of factors such as the...journal article 2024
- document
-
Alhaddad, S.M.S. (author), Keetels, G.H. (author), Mastbergen, Dick (author), van Rhee, C. (author), Lee, Cheng-Hsien (author), Montellà, Eduard Puig (author), Chauchat, Julien (author)This article presents the current state-of-the-art understanding of underwater dilative slope failure (breaching). Experimental investigations are reviewed, providing critical insights into the underlying physics of breaching and pointing out knowledge gaps, which underscore the need for further research. Besides, field observations at several...review 2024
- document
-
Alhaddad, S.M.S. (author), Weij, Dave (author), van Rhee, C. (author), Keetels, G.H. (author)As a result of the dilation of soil matrix, dense submarine sand slopes can temporarily be steeper than the natural angle of repose. These slopes gradually fail by the detachment of individual grains and intermittent collapses of small coherent sand wedges. The key question is whether steep disturbances in a submarine slope grow in size ...journal article 2023
- document
-
Nieuwboer, B.J. (author), van Rhee, C. (author), Keetels, G.H. (author)When dredging rock using a Cutter Suction Dredger the high amount of spillage is problematic, since it prevents an energy efficient removal process. This papers presents a coupled DEM-FVM method to simulate spillage, that can be used for optimizing the design and working method of the Cutter Suction Dredger. In these simulations, the challenge...journal article 2023
- document
-
Montellà, E. P. (author), Chauchat, J. (author), Bonamy, C. (author), Weij, D. (author), Keetels, G.H. (author), Hsu, T. J. (author)In submerged sandy slopes, soil is frequently eroded as a combination of two main mechanisms: breaching, which refers to the retrogressive failure of a steep slope forming a turbidity current, and instantaneous sliding wedges, known as shear failure, that also contribute to shape the morphology of the soil deposit. Although there are several...journal article 2023
- document
-
Keetels, G.H. (author), Chauchat, Julien (author), Breugem, W.P. (author)Reliable prediction of the erosion rate of sediment beds is important for many applications in coastal and river engineering. Theoretical understanding of empirically derived scaling relations is still lacking. This applies in particular for the scaling anomaly between low and high Shields number conditions. In this work, the erosion process is...journal article 2023
- document
-
Heijmeijer, Oliver A. (author), Nobel, Arno J. (author), Keetels, G.H. (author), van Rhee, C. (author)Dredging is the relocation of soil. Before the soil can be transported, it has to be loosened. This can be done hydraulically (jetting) or mechanically (cutting). Often, water jets are used to erode the soil layer. Over time, pickup functions have been derived to predict the amount of erosion corresponding to the flow conditions. However,...journal article 2022
- document
-
Lovato, S. (author), Kirichek, Alex (author), Toxopeus, S.L. (author), Settels, J.W. (author), Keetels, G.H. (author)When investigating the effect of muddy seabeds on marine vessels using Computational Fluid Dynamics (CFD) software, one challenge is to adequately describe the complex non-Newtonian fluid behaviour of mud. Although a number of rheological models have been proposed in the past, mud sediments are often simply regarded either as highly viscous...journal article 2022
- document
-
Lovato, S. (author), Keetels, G.H. (author), Toxopeus, S. L. (author), Settels, J. W. (author)This article presents a new turbulence closure based on the k-ω SST model for predicting turbulent flows of Herschel–Bulkley fluids, including Bingham and power-law fluids. The model has been calibrated with direct numerical simulations (DNS) data for fully-developed pipe flow of shear-thinning and viscoplastic fluids. The new model shows...journal article 2022
- document
-
Lovato, S. (author), Toxopeus, S.L. (author), Settels, J.W. (author), Keetels, G.H. (author)The ship’s resistance and manoeuvrability in shallow waters can be adversely influenced by the presence of fluid mud layers on the seabed of ports and waterways. Fluid mud exhibits a complex non-Newtonian rheology that is often described using the Herschel–Bulkley model. The latter has been recently implemented in a maritime finite-volume CFD...journal article 2022
- document
-
Keetels, G.H. (author), Godderis, L. (author), van de Wiel, B.J.H. (author)Background: Both influenza and SARS-CoV-2 viruses show a strong seasonal spreading in temperate regions. Several studies indicated that changes in indoor humidity could be one of the key factors explaining this. Objective: The purpose of this study is to quantify the association between relevant epidemiological metrics and humidity in both...journal article 2022
- document
-
Schouten, T.D. (author), van Rhee, C. (author), Keetels, G.H. (author)In dredging applications, deep sea mining and land reclamation projects typically large amounts of sediments are transported through pipes in the form of hyper concentrated (40% sediment or more) sediment-water mixtures or slurries. In this paper it is investigated how well a generic Euler-Euler CFD-model is capable to model velocity,...journal article 2021
- document
- Lovato, S. (author), Kirichek, Alex (author), Toxopeus, S (author), Settels, Just W. (author), Talmon, A.M. (author), Keetels, G.H. (author) conference paper 2021
- document
-
Wang, Boyao (author), van Rhee, C. (author), Nobel, Arno (author), Keetels, G.H. (author)In dredging, high pressure water jets are commonly applied to assist the mobilization of soil. This work considers the excavation of cohesive soil. The key objective is to predict the development of the cavity in the soil as a function of the undrained shear strength, translation velocity and hydrodynamic pressure of a single nozzle. A...journal article 2021
- document
-
Lovato, S. (author), Toxopeus, Serge Leon (author), Settels, Just W. (author), Keetels, G.H. (author), Vaz, Guilherme (author)The presence of complex fluids in nature and industrial applications combined with the rapid growth of computer power over the past decades has led to an increasing number of numerical studies of non-Newtonian flows. In most cases, non-Newtonian models can be implemented in existing Newtonian solvers by relatively simple modifications of the...journal article 2021
- document
-
Schouten, T.D. (author), Keetels, G.H. (author), van Rhee, C. (author)In dredging applications, deep sea mining and land reclamation projects typically large amounts of sediments are transported through pipes in the form of hyper concentrated (40% sediment or more) sediment-water mixtures or slurry. These slurries can flow at three different regimes. 1: fully suspended (homogeneous and stratified) 2: partially...conference paper 2019
- document
- Lovato, S. (author), Vaz, Guilherme (author), Toxopeus, Serge Leon (author), Keetels, G.H. (author), Settels, J.W. (author) conference paper 2018
- document
-
Patil, A. (author), Mudiyanselage, Sanduni Disanayaka (author), Bricker, J.D. (author), Uijttewaal, W.S.J. (author), Keetels, G.H. (author)Sliding force and punching pressure were contributing factors to widespread breakwater damage caused during the 2011 Great East Japan Tsunami (Takagi and Bricker, 2015), and were dominant factors causing displacement of caissons from the world’s deepest breakwater: the Kamaishi bay-mouth composite tsunami breakwater (Arikawa et al., 2012;...journal article 2018
- document
-
Keetels, G.H. (author), Goeree, J.C. (author), van Rhee, C. (author)Sediment profiles in open channels are usually predicted by advection-diffusion models. Most basic forms consider the terminal settling velocity of a single particle in still clear water. Alternative forms account for hindered settling at higher concentrations. It is not known, however, how these modifications relate to mass and momentum...journal article 2017
- document
-
Weij, D. (author), Keetels, G.H. (author), Goeree, J.C. (author), van Rhee, C. (author)To model submarine flows of granular materials we propose an extension of the drift-flux approach. The extended model is able to represent dilute suspensions as well as dense granular flows. The dense granwular flow is modelled as a Herschel–Bulkley fluid, with a yield stress that depends on the dispersed phase pressure. Qualitative numerical...journal article 2016