A Multiphase Porous Medium Transport Model with Distributed Sublimation Front to Simulate Vacuum Freeze Drying
A. Warning, J. M. R. Arquiza, A. K. Datta
Cornell University, Ithaca, NY, USA
A continuum, porous medium formulation with non-equilibrium sublimation was developed and validated for freeze drying without and with uniform microwave volumetric heating. The model incorporates the effect of Knudsen flow at low pressure and low permeability freeze drying. The distributed, non-equilibrium sublimation demonstrated that the sublimation front is a sharp boundary for high ice ...
D. Papasidero, F. Manenti
Politecnico di Milano, Dipartimento di Chimica, Materiali e Ingegneria Chimica “Giulio Natta”, Milano, Italy
One big challenge for the food industry is to predict and optimize flavors. The Maillard reaction occurs in food matrices containing carbohydrates and proteins under specific operating conditions. The presented research couples thermal and kinetic modeling to the bread baking process, an ideal field to study this complex set of reactions responsible for many bread flavors. The thermal model ...
M. Luna, P. Trinchero, J. Molinero, J. Löfman, P. Pitkanen, L. Koskinen
Amphos 21 Consulting, Barcelona, Spain
VTT Energy, Espoo, Finland
Posiva, Eurajoki, Finland
The safety assessment of the deep geological repository for nuclear waste of Olkiluoto (Finland) requires the evaluation of the influence of the land uplift (ice withdrawal) in groundwater. With this objective in mind, we have developed a three dimensional reactive transport model of the Olkiluoto, simulating the most relevant deformation zones in a three-dimensional domain. The evolution in ...
Chinese Academy of Sciences, Dalian Institute of Chemical Physics, Beijing, China
We studied the transient characteristics of PEMFC and water transport during PEMFC start-up, concerning the following aspects: Effect of air stoichiometry change on transient behavior of PEMFC, Transient behavior of water transport during PEMFC start-up, and high temperature PEMFC modeling.
D. Yuryev, M. Demkowicz 
Massachusetts Institute of Technology, Cambridge, MA, USA
We describe simulations performed in COMSOL Multiphysics® of the precipitation of helium (He) on solid-state interfaces. The non-uniform precipitation of He at certain interfaces is a result of a heterogeneous energy distribution in the interface plane: He wets high interface energy (“heliophilic”) regions but does not wet low interface energy (“heliophobic”) ones. Using a phase-field model, ...
C. Siegel[1,2], G. Bandlamudi[1,2], P. Beckhaus, and A. Heinzel[1,2]
Zentrum für BrennstoffzellenTechnik (ZBT), Duisburg, Germany
University of Duisburg-Essen, Duisburg, Germany
This study highlights the possibility of using COMSOL Multiphysics for solving large scale PEM fuel cell stack models in the order of several million degrees of freedom (DOF). First, different gas flow channel configurations are solved in order to highlight the fluid flow and pressure behaviour. For these models, the full 3D Navier-Stokes equations are solved. It is seen that the amount of fluid ...
H. Ishimori, K. Endo, H. Sakanakura, M. Yamada, M. Osako
Ritsumeikan University, Kusatsu, Shiga, Japan
National Institute for Environmental Studies, Tsukuba, Ibaraki Prefecture, Japan
This paper presents the numerical simulation model for radiocesium leaching and transporting behavior in municipal solid waste (MSW) landfill and discusses on the design for the required geometry and properties of the impermeable final cover and the soil sorption layer, which work for containment of hazardous waste such as radiocesium-contaminated MSW generated by Fukushima Daiichi nuclear ...
S. Kadam, A. K. Datta
Department of Biological & Environmental Engineering, Cornell University, Ithaca, NY, USA
Turgor pressure loss and pectin degradation result in texture loss during cooking of plant based materials. To simulate texture loss, a simultaneous heat and moisture transfer, pectin degradation in the cell wall material and solid mechanical model was developed at the microscale using finite elements to predict the homogenized Young’s Modulus of the carrot tissue during heating. The model ...
E. R. Blatchley, and B.Z. Sun
Department of Civil Engineering, Purdue University, West Lafayette, IN, USA
Mineral precipitation on to the quartz surface of the lamp jackets in UV disinfection process (fouling) has been recognized as a major problem for UV radiation delivery during disinfection operation. Fouling behavior was observed to be induced thermally and influenced by hydraulic character of the UV disinfection configuration. Fouling process involves momentum, heat, and mass transport within ...
M. Rühl, G. Dietrich, E. Pflug, S. Braun, A. Leson
TU Dresden, Laser and Surface Technology, Dresden, Germany
IWS Dresden, Fraunhofer Institute for Material and Beam Technology, Dresden, Germany
Established joining techniques like welding, soldering or brazing typically are characterized by a large amount of heat load of the components. Especially in the case of heat sensitive structures like MEMS this often results in stress induced deformation and degradation or even damaging of the parts. A back door of this problem are Reactive Multilayer Systems (RMS). These foils consist of ...