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 ...
S.C. Seetharam, D. Jacques
Performance Assessments Unit, Institute for Environment, Health and Safety, Belgian Nuclear Research Centre (SCK•CEN), Mol, Belgium
This paper documents current status in the development of a coupled thermal-hydraulic-chemical-geomechanical numerical suite within COMSOL-MATLAB environment to address soil and concrete applications. The mathematical formulations are based on well-established continuum scale models unifying mass conservation, energy conservation, charge conservation, thermodynamic equilibrium and kinetics and ...
S. Odiba, M. Olea, S. Hodgson, A. Adgar
Teesside University, School of Science and Engineering, Middlesbrough, United Kingdom
This research deals with the design of suitable microreactors for the catalytic oxidation of volatile organic compound (VOCs), using propane as a model molecule. The microreactor considered consists of eleven parallel channels, in which an Au/Cr/γ-Al2O3-catalyzed combustion reaction takes place. Each channel is 0.5 mm diameter and 100 mm long. The catalytic microreactor was simulated for ...
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 ...
A COMSOL Multiphysics®-based Model for Simulation of Methane-Hydrate Dissociation by Injection of Superheated Carbon Dioxide
M. Gharasoo, C. Deusner, N. Bigalke, M. Haeckel
Department of Marine Geosystems, GEOMAR - Helmholtz Centre for Ocean Research, Kiel, Germany
Immense amounts of methane are stored as gas-hydrate deposits in deep layers of marine sediments. This has raised considerable interest to develop strategies for producing natural gas from marine hydrates. One potential production strategy is the injection of supercritical CO2 into methane hydrate-bearing sand layers to release the CH4 as a gas and sequester the CO2 as hydrate. We used COMSOL ...
F.T. Wandschneider, M. Küttinger, P. Fischer, K. Pinkwart, J. Tübke, H. Nirschl
Fraunhofer-Institute for Chemical Technology, Pfinztal, Germany
Karlsruhe Institute for Technology, Karlsruhe, Germany
A two-dimensional stationary model of a vanadium oxygen fuel cell is developed in COMSOL Multiphysics®. This energy storage device combines a vanadium flow battery anode and an oxygen fuel cell cathode. The oxygen reduction reaction generates additional water, leading to a degradation of the catalyst performance over time. A logistic function is introduced to the Butler-Volmer equation in order ...
D. Lahaye, L. Cheng
DIAM, EEMCS Faculty, TU Delft, The Netherlands
Tsinghua University, Beijing, China
In the production of high quality materials by a heat treatment, it is indispensable to accurately predict the temperature inside the furnaces being employed. In this work we develop a turbulent combustion model for the heat being released by gas burners inside a shaft kiln. Turbulent combustion is the strongly coupled phenomena of the chemically reacting fuel and oxygen in a turbulent flow. ...
A. K. R. Paul , R. D. Pal ,
 CSIR-Central Electrochemical Research Institute, Karaikudi, Tamil Nadu, India
 Academy of Scientific and Innovative Research, Chennai, Tamil Nadu, India
A lithium-ion battery comprises of two intercalating electrodes separated by a membrane, sandwiched between aluminum and copper current collecting plates. The battery performance depends upon several parameters and its operating conditions. In this work we developed a model for a lithium iron phosphate battery and validated our results with experimental charge-discharge curves. We however note ...
J. Schöne, A. Körnig, W. Beckert
Fraunhofer IKTS, Dresden, Germany
Reformer and catalytic burners are common components in fuel cell systems, crucial for efficient preparation of fuel and exhaust gases of the fuel cell stack. We intend to show the influence of radiation to the temperature distribution inside of a reformer unit. The model consists of an axisymmetric representation of the inlet-zone and a catalytic porous zone. Fluid flow, convective and ...
C. Butcher, K. Yu
University of Maryland, College Park, MD, USA
The complex internal flow field of a hypersonic air-breathing propulsion engine was modeled using COMSOL Multiphysics® software. This type of flow field can be found in a dual-mode scramjet engine. After creating the geometry, a 2D CFD simulation was run using the High Mach Number Flow physics interface in the CFD Module. A stationary time study was run and the results from the CFD simulation ...