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Kenjeres, S. (author), Zwinkels, S. (author)In the present study, we focus on modeling and simulations of macroscopic behavior of a crowd of people under emergency conditions. We present a newly developed integrated numerical approach, which combines the time-dependent RANS method in predicting the temporal and spatial evolution of a heavy gas turbulent dispersion with the macroscopic...journal article 2019
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Raji, B. (author), Tenpierik, M.J. (author), Bokel, R.M.J. (author), van den Dobbelsteen, A.A.J.F. (author)This paper investigates the potential use of natural ventilation strategies to reduce the energy demand for cooling and mechanical ventilation for high-rise buildings in summer. A 21-storey office building was selected to represent a mechanically ventilated high-rise design in temperate climates. Six natural ventilation scenarios were developed...journal article 2019
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Della Vecchia, Gabriele (author), Cremonesi, Massimiliano (author), Pisano, F. (author)This paper concerns the rheological characterisation of liquefied sands as non-Newtonian Bingham fluids. For this purpose, dam-breaking laboratory tests are often executed and interpreted, offering a viable option to identify the properties of fluidised water-soil mixtures. However, limited attention has been devoted so far to clarify what...journal article 2019
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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
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Wei, P. (author), Mudde, R.F. (author), Uijttewaal, W.S.J. (author), Spanjers, H. (author), van Lier, J.B. (author), de Kreuk, M.K. (author)This study aimed to characterise the gas-liquid flow and mixing behaviour in a gas-mixed anaerobic digester by improving phase interaction modelling using Computational Fluid Dynamics (CFD). A 2D axisymmetric model validated with experimental data was set up using an Eulerian-Eulerian method. Uncertainty factors, including bubble size, phase...journal article 2019
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Zeng, Q. (author), Hekkenberg, R.G. (author), Thill, C.H. (author)Accurate resistance prediction for ships sailing in vertically restricted waterways is highly required to improve the design and operation for large ships entering harbors and for vessels navigating in inland waters. The methods derived from deep water may lead to large errors, and studies considering shallow water effects are needed. As most...journal article 2019
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van Tilborg, Frank (author), van Raemdonck, G.M.R. (author), Sciacchitano, A. (author), Casalino, D. (author)This article analyses the flow field between two 1/8-scale Generalized European Transport System (GETS) models which are placed in a two-vehicle platoon at close distances. Numerical simulations using the lattice Boltzmann method together with a wind tunnel experiment (open jet facility, OJF) were executed. Next to balance measurements,...journal article 2019
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Rubino, A. (author), Pini, M. (author), Kosec, M. (author), Vitale, S. (author), Colonna, Piero (author)Fast and accurate computation of thermo-physical properties is essential in computationally expensive simulations involving fluid flows that significantly depart from the ideal gas or ideal liquid behavior. A look-up table algorithm based on unstructured grids is proposed and applied to non-ideal compressible fluid dynamics simulations. The...journal article 2018
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Renzsch, H.F. (author)While historically sailmaking and saildesign were considered as arts, in the 20th century, mainly from the 1980s onwards, engineering sciences have started to play an important role. Two fields are of particular interest: structural and fluid mechanics. Initially, the sails were tested in the wind tunnel, aggregate flow forces measured and the...doctoral thesis 2018
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Haringa, C. (author), Tang, W. (author), Wang, G. (author), Deshmukh, A.T. (author), van Winden, Wouter A. (author), Chu, Ju (author), van Gulik, W.M. (author), Heijnen, J.J. (author), Mudde, R.F. (author), Noorman, H.J. (author)We assess the effect of substrate heterogeneity on the metabolic response of P. chrysogenum in industrial bioreactors via the coupling of a 9-pool metabolic model with Euler-Lagrange CFD simulations. In this work, we outline how this coupled hydrodynamic-metabolic modeling can be utilized in 5 steps. (1) A model response study with a fixed...journal article 2018
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Haringa, C. (author), Vandewijer, Ruben (author), Mudde, R.F. (author)Steady state multiple reference frame-RANS (MRF-RANS) simulations frequently show strong over-predictions of the mixing time in single-phase, multi-impeller mixing tanks, which is sometimes patched by ad hoc tuning of the turbulent Schmidt-number. In Part I of this work, we experimentally revealed the presence of macro-instabilities in the...journal article 2018
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Haringa, C. (author), Vandewijer, Ruben (author), Mudde, R.F. (author)CFD simulations of mixing in single-phase multi-Rushton stirred tanks based on the RANS methodology frequently show an over-prediction of the mixing time. This hints at an under-prediction of the mass exchange between the compartments formed around the individual impellers. Some studies recommend tuning the turbulent Schmidt number to address...journal article 2018
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Zeng, Q. (author), Thill, C.H. (author), Hekkenberg, R.G. (author), Rotteveel, E. (author)The ITTC57 correlation line, which is derived based on the assumption that the water in which ships advance is infinite deep and wide. However, for ships sailing in the waterway with limited water depth, the frictional resistance will be influenced leading to a decreasing accuracy of the prediction with this correlation line. In this study, a...journal article 2018
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Haringa, C. (author), Mudde, R.F. (author), Noorman, H.J. (author)Euler–Lagrange computational fluid dynamics simulations offer great potential for the integration of transport dynamics and metabolic dynamics in fermentation systems. Since the seminal work of Lapin et al. [1,2], progress has been made, mainly in the analysis of CFD data and translation to laboratory setup designs. Different large-scale...journal article 2018
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Schneiders, J.F.G. (author)A series of techniques is proposed for volumetric air flow measurements that are based upon the principles of particle image velocimetry (PIV). The proposed techniques fall in two categories; part 1 of this dissertation considers measurement data processing using constitutive laws and part 2 focuses on development of a coaxial volumetric flow...doctoral thesis 2017
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Haringa, C. (author)The broth in industrial scale fermentors may contain significant gradients in, for example, substrate concentration, dissolved oxygen and shear rates. From the perspective of microbes in this fermentor, these gradients translate to temporal variations in their environment that may affect their metabolic response. As a result, there may be...doctoral thesis 2017
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Gunyol, O. (author)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...doctoral thesis 2017
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Belligoli, Z. (author), Dwight, R.P. (author), Kok, G. J.P. (author), Lucas, P. (author)This paper presents an approach for updating the epistemic uncertainty of ultrasonic flow meter measurements under non-ideal flow conditions. Instead of re-calibrating the instrument to correct its behavior in these difficult working conditions, a Bayesian calibration of a computer model of the real process is used. The numerical model is...journal article 2017
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Zhang, Y. (author)Wind turbines are operating under very complex and uncontrolled environmental conditions, including atmospheric turbulence, atmospheric boundary layer effects, directional and spatial variations in wind shear, etc. Over the past decades, the size of a commercial wind turbine has increased considerably. All the complex and uncontrolled conditions...doctoral thesis 2017
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- van der Velden, W.C.P. (author) doctoral thesis 2017