|Personal data||Research themes||Ongoing teaching||Publications|
TIPs - Transport phenomena and process engineering
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 Adam Chafaï, PhD.
Multiscale analysis of drying processes
In the field of drying, an important part of our work concentrates on the study of transport processes taking place at the scale of a product, during its drying. We have been interested in various products, from baker's yeast pellets to soils, colloidal suspensions, peppercorns or cocoa beans, in different kind of devices/geometries (laboratory tunnel dryer, fluidized bed, spray dryer, sessile drop, Hele-Shaw cell…). By combining experiments and mathematical modeling, we try to highlight and characterize the key phenomena involved and to develop models, validated experimentally, of the drying kinetics of these products. From the experimental point of view, we have developed various devices, combining continuous measurement of the drying rate and optical characterizations (by the use of microscopes or infrared cameras). From a more fundamental point of view, we are also interested in the quantification and the modeling of the competition that can exist in a porous medium between the evaporation of the liquid and the convective motion induced by capillarity (imbibition). At the scale of the dryer, we participate in several projects aiming at the development, based on a rational approach, of solar dryers, to be implemented within farmer cooperatives in developing countries (Uganda, Cambodia...). As part of a long-standing collaboration with Polytechnique Montréal, we are also interested in the development of alternative devices for the drying of yeast grains (rotary dryer, conical spouted bed...). Selected publications : Van Engeland, C., Spreutels, L., Legros, R., & Haut, B. Convective drying of baker’s yeast containing a carrier. Accepted in Drying Technology. 2018 Sobac, S., Colinet, P., Larbi, Z., & Haut, B. Mathematical modeling of the drying of a spherical colloïdal drop. Submitted to Journal of Colloïd and Interface Science. 2018 Herman, C., Spreutels, L., Turomzsa, N., Konagano, E., & Haut, B. Convective drying of fermented Amazonian cocoa beans (Theobroma cacao var. Forasteiro). Experiments and mathematical modeling. Food and Bioproducts Processing, 108, 81-94. 2018 Talbot, P., Lhote, M., Heilporn, C., Schubert, A., Willaert, F.X., & Haut, B. Ventilated tunnel solar dryers for small-scale farmers organizations: theoretical and practical aspects. Drying Technology, 97, 803-817. 2016