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- Yoo, Jaehoon (author), Kim, Hyoung Tae (author) journal article 2006
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Sobera, M.P. (author), Kleijn, C.R. (author)We study flow and heat transfer to a cylinder in cross flow at Re = 3,900–80,000 by means of three-dimensional transient RANS (T-RANS) simulations, employing an RNG k???? turbulence model. Both the case of a bare solid cylinder and that of a solid cylinder surrounded at some fixed distance by a thin porous layer have been studied. The latter...journal article 2008
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Joint Scalar versus Joint Velocity-Scalar PDF Simulations of Bluff-Body Stabilized Flames with REDIMMerci, B. (author), Naud, B. (author), Roekaerts, D. (author), Maas, U. (author)Two transported PDF strategies, joint velocity-scalar PDF (JVSPDF) and joint scalar PDF (JSPDF), are investigated for bluff-body stabilized jet-type turbulent diffusion flames with a variable degree of turbulence–chemistry interaction. Chemistry is modeled by means of the novel reaction-diffusion manifold (REDIM) technique. A detailed chemistry...journal article 2008
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Haringa, C. (author), Tang, Wenjun (author), Deshmukh, Amit T. (author), Xia, Jianye (author), Reuss, Matthias (author), Heijnen, J.J. (author), Noorman, H.J. (author), Mudde, R.F. (author)The trajectories, referred to as lifelines, of individual microorganisms in an industrial scale fermentor under substrate limiting conditions were studied using an Euler-Lagrange computational fluid dynamics approach. The metabolic response to substrate concentration variations along these lifelines provides deep insight in the dynamic...journal article 2016
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Dighe, V.V. (author), Avallone, F. (author), van Bussel, G.J.W. (author)In this paper, a computational approach, based on the solution of Reynolds-averaged-Navier–Stokes (RANS) equations, to describe the flow within and around a diffuser augmented wind turbine (DAWT) is reported. In order to reduce the computational cost, the turbine is modeled as an actuator disc (AD) that imposes a resistance to the passage of the...journal article 2016
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Abolghasemi, M.A. (author), Piggott, M.D. (author), Spinneken, J (author), Viré, A.C. (author), Cotter, CJ (author), Crammond, S. (author)Embedding tidal turbines within simulations of realistic large-scale tidal flows is a highly multi-scale problem that poses significant computational challenges. Here this problem is tackled using actuator disc momentum (ADM) theory and Reynolds-averaged Navier–Stokes (RANS) with, for the first time, dynamically adaptive mesh optimisation...journal article 2016
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Ubbens, H.H. (author), Dwight, R.P. (author), Sciacchitano, A. (author), Timmer, W.A. (author)Bobsleighs races nowadays are decided upon hundredths of a second. As the margins are that small the aerodynamics of a bobsleigh can play a significant role in a race outcome. This paper investigates the influence of the gap between the nose and the rear cowling of a two-man bobsleigh. The paper especially focusses on the misalignment between...journal article 2016
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Haringa, C. (author), Deshmukh, Amit T. (author), Mudde, R.F. (author), Noorman, H.J. (author)With reaction timescales equal to or shorter than the circulation time, the ideal mixing assumption typically does not hold for large scale bioreactors. As a consequence large scale gradients in extra-cellular conditions such as the substrate concentration exist, which may significantly impact the metabolism of micro-organisms and thereby the...journal article 2017
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Aissa, M.H. (author), Verstraete, Tom (author), Vuik, Cornelis (author)A computational Fluid Dynamics (CFD) code for steady simulations solves a set of non-linear partial differential equations using an iterative time stepping process, which could follow an explicit or an implicit scheme. On the CPU, the difference between both time stepping methods with respect to stability and performance has been well covered in...journal article 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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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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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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Kenjeres, S. (author)This work presents an application of a RANS/LES hybrid approach in simulating flows and turbulent dispersion in complex urban areas. It is demonstrated that the<br/>hybrid approach correctly captures the time-dependent behavior of the wake regions behind buildings, resulting in improvements of the total turbulent kinetic energy and, consequently...journal article 2019
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Dighe, V.V. (author), De Oliveira Andrade, G.L. (author), Avallone, F. (author), van Bussel, G.J.W. (author)The complex aerodynamic interactions between the rotor and the duct has to be accounted for the design of ducted wind turbines (DWTs). A numerical study to investigate the characteristics of flow around the DWT using a simplified duct–actuator disc (AD) model is carried out. Inviscid and viscous flow calculations are performed to understand...journal article 2019
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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