Searched for: collection%3Air
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Vuik, V. (author), Jonkman, Sebastiaan N. (author)
Salt marshes are a characteristic feature of estuaries and coastal seas. They are found in the upper coastal intertidal zones between land and water, which are regularly flooded by tides and surges. They are covered with salt-tolerant vegetation types, such as herbs and grasses. Sheltering from continuous intense hydrodynamic forcing by waves...
abstract 2016
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Willemsen, P.W.J.M (author), Borsje, B.W. (author), Vuik, V. (author), Janssen, S.K.H. (author), Bouma, T. J. (author), Hulscher, SJMH (author)
abstract 2016
document
Qiu, Y. (author), van Gijzen, M.B. (author), van Wingerden, J.W. (author), Verhaegen, M. (author), Vuik, C. (author)
Multilevel sequentially semiseparable (MSSS) matrices form a class of structured matrices that have low-rank off-diagonal structure, which allows the matrix-matrix operations to be performed in linear computational complexity. MSSS preconditioners are computed by replacing the Schur complements in the block LU factorization of the global linear...
report 2015
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Qiu, Y. (author), Van Gijzen, M.B. (author), Van Wingerden, J.W. (author), Verhaegen, M.H.G. (author), Vuik, C. (author)
In this manuscript, we study preconditioning techniques for optimal in-domain control of the Navier-Stokes equation, where the control only acts on a few parts of the domain. Optimization and linearization of the optimal in-domain control problem results in a generalized linear saddle-point system. The Schur complement for the generalized saddle...
report 2015
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Van Zwieten, J.S.B. (author), Sanderse, B. (author), Hendrix, M.H.V. (author), Vuik, C. (author), Henkes, R.A.W.M. (author)
One-dimensional models for multiphase flow in pipelines are commonly discretised using first-order Finite Volume (FV) schemes, often combined with implicit time-integration methods. While robust, these methods introduce much numerical diffusion depending on the number of grid points. In this paper we propose a high-order, space-time...
report 2015
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Knibbe, H. (author), Vuik, C. (author), Oosterlee, C.W. (author)
In geophysical applications, the interest in least-squares migration (LSM) as an imaging algorithm is increasing due to the demand for more accurate solutions and the development of high-performance computing. The computational engine of LSM in this work is the numerical solution of the 3D Helmholtz equation in the frequency domain. The...
journal article 2015
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Knibbe, H.P. (author), Vuik, C. (author), Oosterlee, C.W. (author)
In geophysical applications, the interest in least-squares migration (LSM) as an imaging algorithm is increasing due to the demand for more accurate solutions and the development of high-performance computing. The computational engine of LSM in this work is the numerical solution of the 3D Helmholtz equation in the frequency domain. The...
journal article 2015
document
Van Wijngaarden, W.K. (author), Van Paassen, L.A. (author), Vermolen, F.J. (author), Van Meurs, G.A.M. (author), Vuik, C. (author)
Biogrout is a method for reinforcement of granular soil. In the Biogrout process, calcium carbonate is produced. This solid connects the grains, and therefore the strength of the soil is increased. The calcium carbonate is formed with the use of micro-organisms. Experiments and numerical simulations have been performed to demonstrate the process...
journal article 2015
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Lahaye, D.J.P. (author), Vuik, C. (author)
Networks for the high-voltage distribution of electrical energy are currently undergoing farreaching developments. National power grids are evolving fromstatic entities, producingmainly a uni-directional flow from generation to loads, to more dynamic and decentralized structures. These emerging power systems should accommodate the local...
journal article 2015
document
Qiu, Y. (author), Van Gijzen, M.B. (author), Van Wingerden, J.W. (author), Verhaegen, M. (author), Vuik, C. (author)
In this manuscript, we study preconditioning techniques for optimal in-domain control of the Navier-Stokes equation, where the control only acts on a few parts of the domain. Optimization and linearization of the optimal in-domain control problem results in a generalized linear saddle-point system. The Schur complement for the generalized saddle...
report 2015
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Thomas, R. (author), Lahaye, D.J.P. (author), Vuik, C. (author), Van der Sluis, L. (author)
Simulation of current interruption is currently performed with non-ideal switching devices for large power systems. Nevertheless, for small networks, non-ideal switching devices can be substituted by arc models. However, this substitution has a negative impact on the computation time. At the same time, these simulations are useful to design...
conference paper 2015
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Tang, J.M. (author), Vuik, C. (author), Witteveen, C. (author)
In this report, the recent and future contributions of experts and groups of Delft University of Technology (DUT) on the topic of smart grids (SG) are presented. This may provide guidelines on how DUT can contribute in current and future SG projects, such as the current TKI project on “Smart Grid Evolution (SGE): Developing a service platform...
report 2014
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Van Wageningen-Kessels, F.L.M. (author), Van Lint, J.W.C. (author), Hoogendoorn, S.P. (author), Vuik, C. (author)
We propose and analyze a generic multi-class kinematic wave traffic flow model: Fastlane. The model takes into account heterogeneity among driver-vehicle units with respect to speed and space occupancy: long vehicles with large headways (e.g. trucks) take more space than short vehicles with short headways (e.g. passenger cars). Moreover, and...
journal article 2014
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Knibbe, H.P. (author), Mulder, W.A. (author), Oosterlee, C.W. (author), Vuik, C. (author)
Three-dimensional reverse-time migration with the constant-density acoustic wave equation requires an efficient numerical scheme for the computation of wavefields. An explicit finite-difference scheme in the time domain is a common choice. However, it requires a significant amount of disk space for the imaging condition. The frequency-domain...
journal article 2014
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Qiu, Y. (author), Van Gijzen, M.B. (author), Van Wingerden, J.W. (author), Verhaegen, M. (author), Vuik, C. (author)
In this paper, we consider preconditioning for PDE-constrained optimization problems. The underlying problems yield a linear saddle-point system. We study a class of preconditioners based on multilevel sequentially semiseparable (MSSS) matrix computations. The novel global preconditioner is to make use of the global structure of the saddle-point...
report 2014
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Van Wageningen-Kessels, F.L.M. (author), Hoogendoorn, S.P. (author), Vuik, C. (author), Van Lint, J.W.C. (author)
80 years ago, Bruce Greenshields presented the first traffic flow model at the Annual Meeting of the Highway Research Board. Since then, many models and simulation tools have been developed. We show a model tree with four families of traffic flow models, all descending from Greenshields' model. The tree shows the historical development of...
lecture notes 2014
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Van Wageningen-Kessels, F.L.M. (author), Van Lint, J.W.C. (author), Hoogendoorn, S.P. (author), Vuik, C. (author)
We propose and analyze a generic multi-class kinematic wave traffic flow model: Fastlane. The model takes into account heterogeneity among driver-vehicle units with respect to speed and space occupancy: long vehicles with large headways (e.g. trucks) take more space than short vehicles with short headways (e.g. passenger cars). Moreover, and...
conference paper 2014
document
Van Wageningen-Kessels, F.L.M. (author), Hoogendoorn, S.P. (author), Vuik, C. (author), Van Lint, J.W.C. (author)
conference paper 2014
document
Qiu, Y. (author), Van Gijzen, M.B. (author), Van Wingerden, J. (author), Verhaegen, M. (author), Vuik, C. (author)
This paper studies a new preconditioning technique for sparse systems arising from discretized partial differential equations (PDEs) in computational fluid dynamics (CFD), which exploit the multilevel sequentially semiseparable (MSSS) structure of the system matrix. MSSS matrix computations give a data-sparse way to approximate the LU...
report 2013
document
He, X. (author), Vuik, C. (author)
In this report we explore the performance of the SIMPLER , augmented Lagrangian, ’grad-div’ preconditioners and their variants for the two-by-two block systems arising in the incompressible Navier-Stokes equations. The lid-driven cavity and flow over a finite flat plate are chosen as the benchmark problems. For each problem Reynolds number...
report 2013
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