La Recherche à l'ULB| Données Personnelles | Thématiques de recherche | Charges de cours | Publications |
HAUT Benoît
Unités
Centre Interdisciplinaire de Phénomènes Non-linéaires et de Systèmes Complexes
La recherche en complexité apporte un point de vue unifié sur un grand nombre de phénomènes se manifestant dans les systèmes composés de sous-unités en interaction. Il s'agit d'une branche hautement interdisciplinaire et en plein essor de la science comptemporaine et constitue une interface privilégiée entre les mathématiques, la physique et la chimie d'une part, et les systèmes complexes du monde réel d'autre part, comme rencontrés notamment dans les sciences de la vie. Le Centre est consacré à la recherche sur les systèmes complexes et les disciplines connexes que sont la science du non-linéaire, la physique statistique, la thermodynamique, la chimie physique, la biologie des systèmes, et les techniques de simulations. Il contribue à la promotion de ces sujets par l'organisation de programmes de formation, d'échanges de chercheurs, de conférences, ainsi que par la participation à des projets nationaux et internationaux. Il est composé de chercheurs du corps académique de l'ULB, de mandataires permanents du FRS-FNRS, de chercheurs postdoctoraux et de doctorants. Il est attaché aux Départements de Physique, de Chimie et de Biologie des Organismes de la Faculté des Sciences, ainsi qu'au Département de Chimie et Science des matériaux de la Faculté des Sciences appliquées.
TIPs - Transport phenomena and process engineering
Responsable d'Unité : Oui
The objective of the research carried out at the Transfers, Interfaces and Processes (TIPs) laboratory of the Université libre de Bruxelles (ULB) is the experimental characterization and the mathematical modeling of transport phenomena within systems containing several phases (gas and/or liquid and/or solid), exchanging matter, heat or momentum, through an interface between these phases, at scales between the micron and the millimeter. The research carried out revolves around mainly fundamental and/or generic questions. They have direct applications in the fields of health, environment, heat transfer technologies and agro-food, chemical, microtechnology, materials and space industries. Our current research concerns 9 scientific topics: Drying, Enzymatic processes, Evaporation and boiling, Gas-liquid transfers, Microfluidics, Physiological fluids, Soft/Wet microrobotics, Surface rheology and, as a side research area, the characterization of Ancient hydraulic systems. The TIPs laboratory is composed of 5 professors and approximately 35 researchers. It is divided into two research units : "TIPs - Transport phenomena and process engineering" and "TIPs - Fluid physics". The TIPs laboratory collaborates with a number of scientific and industrial partners in Belgium, Europe, USA, Israel and Canada, in the frame of several networks funded by the European Commission or by the European Space Agency, and also thanks to support at National level (BELSPO, FNRS, Brussels and Walloon Regions). The team investigates mostly fundamental and/or generic questions, i.e. common to several natural or industrial processes. Studied problems most often involve notions of nonlinear dynamics, physical chemistry (equilibrium and non-equilibrium), statistical mechanics, transport phenomena, applied mathematics, ... The used tools are either theoretical (stability analyses, scaling laws, asymptotic techniques, ...), numerical (commercial or 'home-made' software), or experimental (fluid behavior visualization by interferometry, Schlieren, infrared thermography, ...). The TIPs laboratory has an experimental facility devoted to the realization, the characterization and the manipulation of systems including several phases (gas and/or liquid and/or solid), exchanging mass, energy or momentum, at a characteristic length scale between the micron and the millimeter. The lab is part of the Micro-milli platform. It is managed by by Sam Dehaeck, PhD.
Responsable d'Unité : Oui
Au Service TIPs (Transferts, Interfaces et Procédés) de l'ULB, les recherches en cours ont pour but principal de développer de nouvelles méthodes théoriques, numériques et expérimentales, permettant de comprendre et de prédire le comportement de systèmes multiphasiques, et de concevoir ou d'optimiser des procédés industriels de transformation de la matière (minérale, organique, biologique) et de l'énergie. Ces recherches s'articulent essentiellement autour de sept grands thèmes: le mélange, les transferts de matière gaz-liquide, la dynamique des interfaces fluides et leurs instabilités, le mouillage, les milieux poreux, le transfert de chaleur et les changements de phase (évaporation, cristallisation, ...). Le Service est structuré en deux Unités de Recherche complémentaires : l'Unité de Physique des Fluides et l'Unité de Génie Chimique. L'Unité de Physique des Fluides collabore avec de nombreux partenaires scientifiques et industriels en Belgique, en Europe, aux Etats-Unis, en Israël et au Canada, dans le cadre de plusieurs réseaux financés par la Commission Européenne ou par l'Agence Spatiale Européenne, et grâce également aux financements nationaux (BELSPO, FNRS, Régions Bruxelloise et Wallonne). Les thématiques de recherche s'articulent autour de questions principalement fondamentales et/ou génériques, c'est-à-dire communes à de nombreux processus naturels ou industriels. Les problèmes étudiés font le plus souvent intervenir des notions de dynamique non-linéaire, de chimie physique (équilibre et non-équilibre), de mécanique statistique, de phénomènes de transport, de mathématiques appliquées, ... Les outils utilisés sont soit théoriques (études de stabilité, lois d'échelles, techniques asymptotiques, ...), soit numériques (codes commerciaux ou 'maison'), soit expérimentaux (visualisation de comportements des fluides par interférométrie, Schlieren, thermographie infrarouge, ...).
Projets
Multiscale analysis of drying processes
Dans le domaine du séchage, une partie importante de notre travail se concentre sur l’étude des processus de transport se déroulant à l’échelle d’un produit, lors de son séchage. Nous nous sommes intéressés à divers produits, des granulés de levure de boulangerie aux sols, en passant par les suspensions colloïdales, les grains de poivre ou les fèves de cacao, dans différents types d'appareils / géométries (tunnel de laboratoire, lit fluidisé, atomiseur, goutte sessile, cellule de Hele-Shaw…). . En combinant des expériences et une modélisation mathématique, nous essayons de mettre en évidence et de caractériser les phénomènes clés impliqués et de développer des modèles validés expérimentalement de la cinétique de séchage de ces produits. Du point de vue expérimental, nous avons mis au point divers dispositifs associant une mesure en continu du taux de séchage et des caractérisations optiques (à l’aide de microscopes ou de caméras infrarouges). D'un point de vue plus fondamental, nous nous intéressons également à la quantification et à la modélisation de la compétition pouvant exister en milieu poreux entre l'évaporation du liquide et le mouvement de convection induit par capillarité (imbibition).A l'échelle du séchoir, nous participons à plusieurs projets visant au développement, sur une approche rationnelle, de séchoirs solaires, à mettre en œuvre au sein de coopératives d'agriculteurs de pays en développement (Ouganda, Cambodge ...). Dans le cadre d'une collaboration de longue date avec Polytechnique Montréal, nous nous intéressons également au développement de dispositifs alternatifs pour le séchage des grains de levure (séchoir rotatif, lit à bec conique ...).Publications sélectionnées: Van Engeland, C., L. Spreutels, R. Legros, & amp; Haut, B. Séchage par convection de la levure de boulanger contenant un support. Accepté en technologie de séchage. 2018 Sobac, S., Colinet, P., Larbi, Z., & amp; Haut, B.Modélisation mathématique du séchage d'une goutte colloïdale sphérique. Soumis au Journal of Colloïd et à Interface Science. 2018. Herman, C., Spreutels, L., Turomzsa, N., Konagano, E., & amp; Haut, B. Séchage par convection de fèves de cacao d'Amazonie fermentées (Theobroma cacao var. Forasteiro). Expériences et modélisation mathématique. Transformation des aliments et des bioproduits, 108, 81-94. 2018. P. Talbot, M. Lhote, C. Heilporn, A. Schubert, F. Willaert, & amp; Haut, B. Séchoirs solaires à tunnel ventilé pour les organisations de petits agriculte
Analysis of ancient hydraulic systems
For several years, we have developed a collaboration with archaeologists in order to analyze ancient hydraulic systems. It is commonly accepted that the Romans possessed a technical mastery of water supply. Nevertheless, few writings on this engineering practice are available. Moreover, due to the scientific knowledge in the field of fluid mechanics during the Roman period, these writings do not contain the usual modern information on the characterization of a hydraulic system. However, thanks to the current knowledge in fluid mechanics, it is now possible to simulate the flow that was taking place in a hydraulic remains presenting a good state of conservation. It is therefore possible to supplement the usual field information with data such as flow rates, velocity and pressure fields, energy losses, yields... In recent years, we were interested in fountains found in large houses in the southern part of the ancient Roman city of Apamea (Byzantine times). We were able to characterize their functioning using classical fluid mechanics approaches. The analysis of the results obtained clearly shows that these fountains were supplied with water by an aqueduct and that this feed was technically feasible in view of the remains of the Byzantine aqueduct still present in the north of the city. We were also interested in a peculiar system that can be observed within the ruins of the city of Perge (Turkey). During the Roman Imperial Period, at the middle of the main street of the city, a water channel was operated. This channel has peculiar dimensions and blocks were positioned inside it at a regular interval. By using open surface flow theory, we have been able to characterize the flow in this system and in diversions originating from it. Selected publications : Vekemans, O., & Haut, B. Hydraulic analysis of the water supply system of the Roman city of Perge. Journal of Archaeological Science: Reports, 16, 322-329. 2017 Haut, B., Zheng, X.Y., Mays, L., Han, M., Passchier, C., & Angelakis, A.N. Evolution of rainwater harvesting in urban areas through the millennia. A sustainable technology for increasing water availability. In W.J.H. Willems & H.P.J. van Schaik (Eds.), Water and Heritage. The Netherlands: Sidestone Press. 2015 Vannesse, M., Haut, B., Debaste, F., & Viviers, D. Analysis of three private hydraulic systems operated in Apamea during the Byzantine period. Journal of Archaeological Science, 46, 245-254. 2014
In this research project, we aim to describe the transport phenomena (mass and momentum) taking place inside and around a bubble/drop within a gas-liquid contactor. By combining theoretical (balance equations, stability analysis, asymptotic techniques...), numerical (commercial codes, “home-made” codes) and experimental tools (essentially implementing optical diagnostic techniques: shadowing or interferometry), we can obtain original results, related for example to the dynamics of bubbles in microchannels (paying a special attention to the inertial and capillary migration forces, as well as to the role of surfactants.), the dynamics and morphology of unconfined ellipsoidal bubbles or the coupling between flow, bubble-liquid or gas-droplet mass transfer and chemical reaction. Selected publications : Atasi, O., Haut, B., Pedrono, A., Scheid, B., & Legendre, D. Infuence of soluble surfactants and deformation on the dynamics of centered bubbles in cylindrical microchannels. Langmuir (published online). 2018 Rivero-Rodriguez, J., & Scheid, B. Bubble dynamics in microchannels: internial and capillary migration forces. Jounal of Fluid Mechanics, 842, 215-247. 2018 Mikaelian D., Haut B., & Scheid B., Bubbly flow and gas-liquid mass transfer in square and circular microchannels for stress-free and rigid interfaces: dissolution model, Microfluidics & Nanofluidics, 19, 899-911. 2015 Mikaelian, D., Larcy, A., Cockx, A., Wylock, C., & Haut, B. Dynamics and morphology of single ellipsoidal bubbles in liquids. Experimental Thermal and Fluid Science, 64, 1-12. 2015
Transport phenomena in human lungs
Regarding the transport phenomena in the respiratory system, we have two distinct, but coupled, interests. The first objective of our research is to go towards a better understanding of the dynamics of the bronchial mucus, in healthy and unhealthy people. Human bronchi are covered with a thin layer of mucus. This layer acts as a trap for inspired fine particles and microorganisms. However, today, the dynamics of the bronchial mucus is still poorly understood. In addition, it is known that, in the context of certain diseases such as asthma and cystic fibrosis, this dynamics is significantly impaired. In collaboration with the pulmonology department of the Erasme Hospital, our goal is to improve the understanding of the bronchial mucus dynamics by combining in silico (modelling and simulation) and in vitro (laboratory experiments) studies. A specific objective is to analyse the coupling, potentially very important, between the rheology of the mucus and the respiratory conditions (respiration frequency, breathing air temperature and humidity…). Another of our objectives is to understand how the heterogeneity of the lungs (whether natural or induced by pathologies) influences the exchange processes within it (water, heat, oxygen transport). In this context, we are interested in describing the dynamics of the NO, a physiological molecule that can be considered as a marker of different phenomena. In particular, in collaboration with the Karolinska Institute (Sweden), we are studying how this molecule can be used as a tool for monitoring respiratory function on the International Space Station. Selected publications : Karamaoun, C., Sobac, B., Mauroy, B., Van Muylem, A., & Haut, B. New Insights into the Mechanisms Controlling the Bronchia Mucus Balance. PLOS One, published 22 June 2018 Karamaoun, C., Haut, B., & Van Muylem, A. A new role for the exhaled nitric oxide as a functional marker of peripheral airway calibre changes: a theoretical study. Journal of Applied Physiology, 124, 1025-1033. 2018 Karamaoun, C., Van Muylem, A., & Haut, B. Modelling of the nitric oxide transport in the human lungs. Frontiers in Physiology, 7, 255. 2016
At the scale of the interface, our objective is to highlight and characterize the complex coupling that can exist between diffusion, convection and chemical reactions, during the absorption of CO2 in a liquid. We combine an experimental approach, based on interferometry, and theoretical (stability analysis) and numerical approaches. At the scale of the device, our goal is to integrate the results obtained at the scale of the gas-liquid interface into classical chemical engineering approaches, in order to contribute to the optimization or the design of different kind of processes for the capture of CO2, based on absorption in amine solutions or on the formation of CO2 hydrates. Selected publications : Wylock, C., Rednikov, A., Colinet, P., & Haut, B. Experimental and numerical analysis of buoyancy-induced instability during CO2 absorption in NaHCO3-Na2CO3 aqueous solutions. Chemical Engineering Science, 151, 232-246. 2017 Douieb, S., Fradette, L., François, B., & Haut, B. Impact of the fluid flow conditions on the formation rate of carbon dioxide hydrates in a semi-batch stirred tank reactor. AIChE Journal, 61(12), 4387-4401. 2015 Wylock, C., Rednikov, A., Haut, B., & Colinet, P. Nonmonotonic Rayleigh-Taylor instabilities driven by gas-liquid CO2 chemisorption. Journal of Physical Chemistry B, 118(38), 11323-11329
Transport phenomena in the cardiovascular system
Regarding the transport phenomena in the cardiovascular system, our interest lies in the ballistocardiography (BCG) technique. It is a medical technique consisting in measuring, thanks to sensors, the small movements of the body induced by the blood circulation. It is used in particular on the International Space Station, to monitor the time evolution of the heart health of astronauts. Measured signals have been shown to be good indicators of the heart function. Nevertheless, quantitative links between physiological parameters of the heart and the signals measured in BCG have not yet been fully established. In this frame, in collaboration with the cardiology department of the Erasme Hospital (Dr. Pierre-François Migeotte), we develop the fundamental scientific knowledge behind BCG. For this, mathematical models of the body movements induced by the blood flow in the arteries are established, by the combination of fluid mechanics and analytical mechanics approaches. Then, these models are simulated and challenged against BCG signals obtained on Earth, under well-defined conditions, and on patients for whom certain cardiac parameters have been altered in a known manner.
