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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
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Fu, Runnan (author), Pađen, I. (author), Garcia Sanchez, C. (author)Due to lack of information and long geometry generation times, tree geometries are usually oversimplified or even ignored in Computational Fluid Dynamic (CFD) simulations that predict wind and pollutant dispersion in urban areas. Nevertheless, trees are known to impact local wind patterns and air quality levels. Thus, in this paper we explore...journal article 2024
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Muscari, C. (author), Schito, Paolo (author), Viré, A.C. (author), Zasso, Alberto (author), van Wingerden, J.W. (author)Actuator line modeling of wind turbines requires the definition of a free-stream velocity in a computational mesh and a regularization kernel to project the computed body forces onto the domain. Both choices strongly influence the results. In this work, a novel velocity sampling method—the so-called effective velocity model (EVM)—is...journal article 2024
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Jonker, R. G. (author), AlYousif, A.Y. (author), Hofland, Bas (author), Antonini, A. (author), Zoon, Arthur (author), Smith, Gregory (author)This study treats a detached homogenous low-crested structure (HLCS) made of Cubipod concrete elements placed seaward of a vertical wall (forming a basin in between) to reduce overtopping. Assessing the complex hydrodynamics and effects of changing the geometry of such a system in relation to overtopping reduction is challenging. The...journal article 2024
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Ramaekers, M. J.F.G. (author), van der Vlugt, I.B. (author), Westenberg, J. J.M. (author), Perinajová, R. (author), Lamb, H. J. (author), Wildberger, J. E. (author), Kenjeres, S. (author), Schalla, S. (author)Thoracic aortic aneurysm (TAA) is a local dilation of the thoracic aorta. Although universally used, aneurysm diameter alone is a poor predictor of major complications such as rupture. There is a need for better biomarkers for risk assessment that also reflect the aberrant flow patterns found in TAAs. Furthermore, hypertension is often...journal article 2024
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Perinajová, R. (author), van Ooij, Pim (author), Kenjeres, S. (author)A long-time exposure to lack of oxygen (hypoxia) in some regions of the cerebrovascular system is believed to be one of the causes of cerebral neurological diseases. In the present study, we show how a combination of magnetic resonance imaging (MRI) and computational fluid dynamics (CFD) can provide a noninvasive alternative for studying...journal article 2023
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Dutta, Debasish (author), Afzal, Mohammad Saud (author), Alhaddad, S.M.S. (author)This study utilizes three-dimensional simulations to investigate scour in combined wave–current flows around rectangular piles with various aspect ratios. The simulation model solves the Reynolds-averaged Navier–Stokes (RANS) equations using the k–ω turbulence model, and couples the Exner equation to compute bed elevation changes. The model also...journal article 2023
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Wang, J. (author), Yan, Xin ping (author), Boersma, B.J. (author), Lu, Ming jian (author), Liu, Xiaohua (author)Printed circuit heat exchangers (PCHE) are designed to improve heat recovery and energy saving in supercritical CO<sub>2</sub> (S-CO<sub>2</sub>) power cycles. In the current study, a modified channel PCHE is proposed based on the regular straight channel and a zigzag channel. The thermal–hydraulic performance of four different types of PCHE...journal article 2023
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Perinajová, R. (author), Álvarez-Cuevas, Concepción Borrás (author), Juffermans, Joe (author), Westenberg, Jos (author), Lamb, Hildo (author), Kenjeres, S. (author)There is a pressing need to establish novel biomarkers to predict the progression of thoracic aortic aneurysm (TAA) dilatation. Aside from hemodynamics, the roles of oxygen (O<sub>2</sub>) and nitric oxide (NO) in TAA pathogenesis are potentially significant. As such, it is imperative to comprehend the relationship between aneurysm presence...journal article 2023
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Holkema, K. J. (author), Aalbers, C. (author), Wellens, P.R. (author)In head waves, water jet impacts due to run up can occur as a result of the structural configuration of some floating structures, reducing workability. Wave attenuation near the floater may reduce the risk of water jet impacts. This paper presents a numerical study of the performance and attenuation mechanisms of various plate type fixed free...journal article 2023
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Mata, Marisol Irías (author), van Gent, M.R.A. (author)Numerical modelling of wave interaction with rock-armoured rubble mound breakwaters has been performed to study wave overtopping. The influences of the slope angle, a berm in the seaward slope, a protruding crest wall, a recurved parapet, and the wave steepness have been studied using a validated CFD model (OpenFOAM). The numerical modelling...journal article 2023
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Zou, P. (author), Ruiter, N. (author), Bricker, J.D. (author), Uijttewaal, W.S.J. (author)The effects of surface roughness as induced by marine fouling on the hydrodynamic forces on a submerged floating tunnel (SFT) are experimentally and numerically investigated in detail at Reynolds numbers Re = 8.125 × 10<sup>3</sup>–5.25 × 10<sup>4</sup>. A sensitivity analysis to different roughness parameters including roughness height,...journal article 2023
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Begall, Moritz J. (author), Schweidtmann, A.M. (author), Mhamdi, Adel (author), Mitsos, Alexander (author)Computational Fluid Dynamics (CFD) is a powerful tool which can help with the geometry optimization of continuous milli-scale reactors, which often are highly complex devices. Attempting to perform this optimization by manually modifying and testing geometry configurations can however be tedious and computationally inefficient. Addressing...journal article 2023
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van der Eijk, M. (author), Wellens, P.R. (author)The numerical prediction of two-phase flows with an interface is challenging, to a considerable extent because of the high density ratio at the interface. Numerical results become affected by momentum losses, diverging spurious interface velocities, free surface distortion, and even numerical instability. To prevent issues like these,...journal article 2023
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Kamel Targhi, Elahe (author), Emami Niri, Mohammad (author), Zitha, P.L.J. (author)Cross-linked polymer gel is widely used in the oil and gas industry to block high permeability conduits and reduce water cut. The complex nature of this fluid, especially regarding flow in porous media, makes its numerical simulation very time-consuming. This study presents an approach to designing an Artificial Neural Network (ANN) model...journal article 2023
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Wei, P. (author), Uijttewaal, W.S.J. (author), Spanjers, H. (author), van Lier, J.B. (author), de Kreuk, M.K. (author)Gas-mixing is commonly applied in anaerobic digesters, yet the resulting flow and hydraulic mixing are difficult to evaluate because of limited full-scale experimental data and uncertainties in integrating sludge rheological data. This study used computational fluid dynamics (CFD) to assess the impact of treated sludge rheology on flow and...journal article 2023
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Puiman, L. (author), Almeida Benalcazar, E.F. (author), Picioreanu, C. (author), Noorman, H.J. (author), Haringa, C. (author)In large-scale syngas fermentation, strong gradients in dissolved gas (CO, H<sub>2</sub>) concentrations are very likely to occur due to locally varying mass transfer and convection rates. Using Euler-Lagrangian CFD simulations, we analyzed these gradients in an industrial-scale external-loop gas-lift reactor (EL-GLR) for a wide range of...journal article 2023
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Porcarelli, A. (author), Kruljević, B. (author), Langella, I. (author)NO<sub>x</sub> formation in premixed, highly-strained, pure hydrogen-air flamelets is investigated at lean conditions. Detailed-chemistry, one-dimensional and two-dimensional simulations are performed on a reactants-to-products configuration with varying applied strain rate. The results highlight for the first time for lean pure-hydrogen...journal article 2023
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Mauro, F. (author), Valentina, Enrico Della (author), Ferrari, Victor (author), Begovic, Ermina (author)The increasing demand for offshore operations in deep water implies the necessity to predict station-keeping ability of offshore vessels since the early stages of design. To this end, besides developing sufficiently fast and accurate methodologies for the equilibrium resolution of the forces acting on the ship, it is of utmost importance to...journal article 2023
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Zou, P. (author), Kim, Taeksang (author), Bricker, J.D. (author), Uijttewaal, W.S.J. (author)The modelling of complex free surface flows is challenging due to the mobility and deformability of the interface and air entrainment characteristics, which are highly affected by turbulence. With the framework of Reynolds averaged Navier–Stokes (RANS) models and the volume of fluid (VOF) method, turbulence quantities at the air–water...journal article 2023