Danish Technological Institute, Aarhus C, Denmark
The use of the finite element method for understanding and analyzing the freezing and drying processes of food products is in focus in this paper. The objective of this study is to develop a model that can predict temperature distribution and weight loss of food products during the freezing and drying processes. The problem was solved by utilizing heat, mass transfer and moving mesh model. In ...
Modeling Heat and Moisture Transport During Hydration of Cement-Based Materials in Semi-Adiabatic Conditions - new
E. Hernandez-Bautista[1,2], D. Bentz, S. Sandoval-Torres, P. Cano-Barrita
National Institute of Standards and Technology, Gaithersburg, MD, USA
Instituto Politécnico Nacional/CIIDIR Unidad Oaxaca, Oaxaca, México
The process of accelerated curing of pre-cast concrete has a significant importance in the thermal behavior of concrete. A multiphysics model that describes hydration and heat and mass transport in cement based materials was developed. The hydration reactions are described by a maturity function that uses the equivalent time concept, thereby describing the change in the degree of hydration based ...
O. Silva , E. Abarca , J. Molinero , U. Kautsky 
 Amphos 21 Consulting, Barcelona, Spain
 Swedish Nuclear Fuel and Waste Management Co., Stockholm, Sweden
Radionuclide sorption is often simulated using a lumped approach where retention processes are represented by the distribution coefficient (Kd), which relates the radionuclide mass retained in the solid phase to its aqueous concentration. Classical Kd-based simulations rely on two strong assumptions: Kd depends on soil properties and is constant in time. However, sorption processes depend also ...
A. Nanduri , P. L. Mills ,
 Department of Chemical and Natural Gas Engineering, Texas A&M University - Kingsville, Kingsville, TX, USA
The Fischer-Tropsch Synthesis (FTS) is a highly exothermic condensation polymerization reaction of syngas (CO+H2) in the presence of Fe/Co/Ru-based catalysts to produce a wide range of paraffins, olefins and oxygenates, the latter of which is often called syncrude. Multi-Tubular Fixed Bed Reactors (MTFBR) and Slurry Bubble Column reactors (SBCR) are widely employed for FTS processes . To ...
T. Marin-Alvarado ,
 M4Dynamics, Toronto, ON, Canada
An external library, M4Dlib , has been developed to solve multiphysics problems coupled to solution thermodynamics. This approach extends the local equilibrium concept to multiphysics modeling by incorporating a full Gibbs energy minimization routine at each numerical node to calculate the equilibrium based on global temperature, enthalpy or concentration conditions (Figure 1). The ...
Nils Lavesson , Charles Doiron ,
 ABB Corporate Research, Västerås, Sweden
 ABB Corporate Research, Baden-Dättwil, Switzerland
INTRODUCTION: Many electrical insulation systems use a combination of gas and solid media. Typical examples considered here include the combination of solid epoxy insulation and SF6 in a gas insulated subsystem (GIS). To understand how such a system performs under DC voltages, accurate modelling of the conduction of charge and the electric field distribution is needed. To model the solid ...
Modeling of Packed Bed Reactors: Hydrogen Production by the Steam Reforming of Methane and Glycerol - new
A. Dixon, B. MacDonald, A. Olm
Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, MA, USA
The conventional route to hydrogen production is by steam reforming of methane (MSR) in a multitubular packed bed. With the increasing use of biodiesel as a renewable fuel, interest has grown in steam reforming of the excess glycerol produced as a side product (GSR). We use COMSOL Multiphysics® software to model a tubular packed bed reactor, solving a single pellet model at each point. The ...
J. P. Wojeicchowski , A. P. Ramos , J. S. Sousa , L. G. Maciel , M. M. Pariona ,
 Universidade Estadual de Ponta Grossa, Ponta Grossa, PR, Brasil
 Universidad Peruana Unión, Juliaca, Peru
O objetivo deste trabalho foi modelar a perda de umidade de bananas Caturra com os modelos empíricos e com o software COMSOL Multiphysics, definindo os coeficientes convectivo de transferência de massa e difusivo. O valor obtido para coeficiente de difusão, com base no ajuste matemático da 2ª Lei de Fick para cilindros foi de 1,89.10-9 m²/s. O valor do coeficiente convectivo de transferência de ...
S. Manoj, R. Giri, S. Selvakumar
Rajalakshmi Engineering College, Chennai, Tamil Nadu, India
Gaseous exhaust of different industries contains dust particles of different chemical precipitates that are harmful for the environment. Electrostatic Precipitators are very often used in industries like power plant to filter their gaseous exhaust and to prevent the atmosphere to being polluted. Electrostatic Precipitators are very efficient in dust particle collection from the flue gas. ...
T. Marin-Alvarado ,
 M4Dynamics, Toronto, ON, Canada
During solidification of a multicomponent liquid, either a metal alloy, a sulphide matte or an oxide slag system, the process is highly dependant not only on temperature but in composition as well. The thermodynamic properties of the system will dictate what phases or mixtures precipitate from the liquid and their compositions, which are different from the original composition of the liquid, ...