References of "Toye, Dominique"
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See detailSolid-liquid suspension of microcarriers in stirred tank bioreactor - Experimental and numerical analysis
Delafosse, Angélique ULiege; Loubière, Céline; Calvo, Sébastien ULiege et al

in Chemical Engineering Science (in press)

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See detailAnalysis of PIV measurements using modal decomposition techniques, POD and DMD, to study flow structures and their dynamics within a stirred-tank reactor
de Lamotte, Anne ULiege; Delafosse, Angélique ULiege; Calvo, Sébastien ULiege et al

in Chemical Engineering Science (2018)

The present work is a comparative analysis of Proper Orthogonal Decomposition (POD) and Dynamic Mode Decomposition (DMD) computed on experimental turbulent velocity fields measured in a 20L-tank stirred ... [more ▼]

The present work is a comparative analysis of Proper Orthogonal Decomposition (POD) and Dynamic Mode Decomposition (DMD) computed on experimental turbulent velocity fields measured in a 20L-tank stirred by two Rushton impellers at two rotating speeds, N = 150 and 300 rpm. POD identifies flow structures that optimally capture the total kinetic energy of the flow, while DMD identifies structures that significantly contribute to the dynamics of the flow. The experimental data, i.e. the instantaneous radial and axial velocity fields, come from 2-D Particle Image Velocimetry (PIV). The flow motion is turbulent, and it occurs over a wide range of length and time scales, from equipment-dependent large-scale coherent structures to the smallest-scale eddies where energy dissipation takes place. It thus provides an interesting benchmark case for the comparison between POD and DMD, which are based on energy and dynamic analysis, respectively. POD analysis reveals that the most energetic structures are related to the inherent periodic unsteadiness due to the relative motion between the rotating impeller blades and the non-moving baffles. Apart from the mean field, the first most energetic group of modes is related to trailing vortices induced by the Rushton turbines and is associated to a frequency equivalent to the blade passage frequency and its overtones. The second most energetic group of modes is related to vortical structures in the impeller stream and is associated to a frequency equivalent to the rotating speed. DMD analysis identifies flow structures that are found similar to these most energetic modes, although differences appear due to the fact that DMD isolates structures associated to a single frequency and their corresponding growth/decay rate. As in POD, the relative importance of each DMD mode can be estimated using an appropriately defined energy criterion. Comparison of the results from both modal decomposition methods points out their complementarity and their potential for describing the spatial and time characteristics of the flow within a stirred tank. [less ▲]

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See detailInvestigating the effects of hydrodynamics and mixing on mass transfer through the free-surface in stirred tank bioreactors
de Lamotte, Anne ULiege; Delafosse, Angélique ULiege; Calvo, Sébastien ULiege et al

in Chemical Engineering Science (2017), 172

In stirred-tank bioreactors, flow structures of various length and time scales are implied in scalar transport phenomena, such as gas species transfer through the liquid free-surface and their ... [more ▼]

In stirred-tank bioreactors, flow structures of various length and time scales are implied in scalar transport phenomena, such as gas species transfer through the liquid free-surface and their homogenization in the bulk. A proper understanding of the underlying mechanisms, i.e. hydrodynamics, mixing and mass transfer, and of their interactions is required to design and develop reliable and efficient production-scale bioprocesses. The objective of the present work is to experimentally investigate the coupling between gas-liquid mass transfer of oxygen with mixing efficiency and circulation patterns inside an arbitrarily chosen stirred-tank configuration aerated through the liquid free-surface, a baffled 20 L-vessel agitated by two Rushton turbines. Based on global parameter values, the most appropriate rotating speed, N = 300 rpm, is selected in order to further study local hydrodynamic quantities using Particle Image Velocimetry (PIV), as well as mixing and mass transfer dynamics using Planar Laser-Induced Fluorescence (PLIF). The results obtained with these local experimental methods are analyzed in detail. Their averages are first successfully compared to global data. Statistical analysis of their spatial distributions show that large-scale flow patterns significantly influence mass transfer through the free-surface of the stirred tank. Even if global measurements show that global characteristic times for mixing and mass transfer differ by two orders of magnitude, local experimental characterization shows persistent vertical gradients of dissolved gas concentrations. So the dissolved gas concentration is not as perfectly uniform as one might expect. [less ▲]

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See detailApproche par modèle de compartiments pour la modélisation des bioréacteurs
Delafosse, Angélique ULiege; Calvo, Sébastien ULiege; Toye, Dominique ULiege

Scientific conference (2017, November 09)

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See detailRecent Evolutions and Trends in the Use of Computer Aided Chemical Engineering for Educational Purposes at the University of Liège
Léonard, Grégoire ULiege; Belboom, Sandra ULiege; Toye, Dominique ULiege et al

in Computer Aided Chemical Engineering (2017)

The present paper addresses the evolution and perspectives in the teaching of CAPE methods in the Department of Chemical Engineering at the University of Liège. The transition that happened in the 90ies ... [more ▼]

The present paper addresses the evolution and perspectives in the teaching of CAPE methods in the Department of Chemical Engineering at the University of Liège. The transition that happened in the 90ies with the arrival of commercial software is highlighted, as the learning outcomes evolved from the ability of building programs to solve chemical engineering problems towards the ability to use complex commercial software and to understand their limitations. Moreover, CAPE methods were extended to non-dedicated CAPE courses, which is illustrated here by the goals and challenges of their use in courses like “Reactor Engineering” and “Life Cycle Analysis”. It was observed that students sometimes assume that CAPE softwares provide straightforward and trustworthy solutions without the need of understanding their mathematical bases and assumptions. Thus, solutions to make students aware of these limitations are proposed, including the creation of an integrated project focussing on complex multi-disciplinary issues, evidencing the need for critical input from the operator. [less ▲]

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See detailNew models to predict microcarriers just-suspended state in bioreactors for stem cell culture.
Loubière, Céline; Olmos, Eric; Guedon, Emmanuel et al

Conference (2017, October)

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See detailNew models to predict microcarriers just-suspended state in bioreactors for stem cell culturel
Loubière, Céline; Olmos, Eric; Guedon, Emmanuel et al

Conference (2017, July)

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See detailSTUDY ON THE STRUCTURAL EVOLUTION OF SEWAGE SLUDGE DURING CONVECTIVE DRYING
Li, Jie; Fraikin, Laurent ULiege; Salmon, Thierry ULiege et al

Poster (2017, June 19)

The structure of the sludge sample continues changing during drying as a result of the shrinkage phenomenon. Then the exchange area becomes smaller and the drying rate decreases. The sludge collected in a ... [more ▼]

The structure of the sludge sample continues changing during drying as a result of the shrinkage phenomenon. Then the exchange area becomes smaller and the drying rate decreases. The sludge collected in a wastewater treatment plant (Grosses Battes WWTP, Belgium) was chosen for both lab-scale experiment and pilot-scale experiment. X-ray macrotomography (resolution: 0.36 mm per pixel) and X-ray microtomography (resolution: 41 μm per pixel) were used to explore the structure evolution of the sludge bed and the single extrudate respectively. 2D cross-sections of the sludge bed and the single extrudate were acquired, which supply a convenient way to investigate the evolution of the structure. The results show that the structure of both the sludge bed and the single extrudate distinctly changes during the drying process. [less ▲]

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See detailNew models for predicting microcarrier just-suspended state in bioreactors
Loubière, Céline; Olmos, Eric; Guedon, Emmanuel et al

Poster (2017, May)

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See detailX-ray tomography : a tool for revealing local distribution of liquid in structured packed columns
Toye, Dominique ULiege

Conference (2017, May)

Presentation of the x-ray tomography setup and of the experimental results relative to the fluid distribution and to the flow morphology in a column packed with high performance packing (Mellapak 752Y ... [more ▼]

Presentation of the x-ray tomography setup and of the experimental results relative to the fluid distribution and to the flow morphology in a column packed with high performance packing (Mellapak 752Y). The influence of liquid flowrate and of liquid viscosity is addressed. Results are used to get information required to model the mass-transfer performance in the column. [less ▲]

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See detailInfluence of sawdust addition on drying of wastewater sludges: Comparison of structural characteristics
Li, Jie; Plougonven, Erwan ULiege; Fraikin, Laurent ULiege et al

in Drying Technology (2017), 35(8), 925-932

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See detailIntegrated Project with Focus on Energy Transition and Circular Economy for Developing Engineering Students' Soft Skills
Léonard, Grégoire ULiege; Pfennig, Andreas ULiege; Toye, Dominique ULiege et al

Poster (2016, September 05)

The present work reports the experience of an integrated project developed at the University of Liege for master students in chemical engineering. The goals are to promote the acquisition of soft skills ... [more ▼]

The present work reports the experience of an integrated project developed at the University of Liege for master students in chemical engineering. The goals are to promote the acquisition of soft skills and to consolidate technical knowledge by integrating and linking chemical engineering disciplines usually taught separately. A case study was selected to address some of the challenges related to energy transition: students had to design the energy system of a remote island and make it as energy independent and CO2-neutral as possible by 2030. The course of action during the academic year, the assessment of soft skills, and the tools offered to ease the mentoring and encourage the acquisition of soft skills are described. Not all implemented techniques performed equally well, and this project finally appeared to be a challenge for the teaching team as well. [less ▲]

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