Rensselaer Polytechnic Institute, Troy, NY, USA
A model was developed to simulate the reaction, concentration field, flow field, and temperature distribution inside a Claus reactor for converting hydrogen sulfide to sulfur. The model considered two ideal reactors, a continuous stirred tank reactor and a plug flow reactor. As expected, two ideal reactors showed much different behaviors in terms of reactant conversion and operating ...
V. Srivastava ,
 Naval Materials Research Laboratory (NMRL), Defence Research and Development Organization (DRDO), Ambernath, Thane, Maharashtra, India
2D-modeling of arc welding in butt-joint configuration was performed in this study considering thermal-structural interactions. Thermal behavior was modeled in COMSOL Multiphysics® using the Heat Transfer Module with weld heat input as a Gaussian pulse whereas structural behavior using Structural Mechanics Module. Thermal-elastic-plastic behavior model based on Von Mises yield criteria and ...
S. Pramanik, M. Mishra
Indian Institute of Technology Ropar, Rupnagar, Punjab, India
Viscous fingering (VF) instability has been extensively studied over past several decades in the context of various industrial, environmental and chemical processes. We try to model miscible VF at pushed or pulled interfaces using COMSOL Multiphysics®. We study the effect of the positive and negative log-mobility ratio on the fingering instability. Numerical simulation has been performed in 2D ...
Diffusion and Reaction in Fe-Based Catalyst for Fischer-Tropsch Synthesis Using Micro Kinetic Rate Expressions - new
A. Nanduri, P. L. Mills
Department of Chemical & Natural Gas Engineering, Texas A&M University, Kingsville, TX, USA
Fischer-Tropsch synthesis (FTS) is a highly exothermic 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, often known as syncrude. Multi-Tubular Fixed Bed Reactors (MTFBR) and Slurry Bubble Column Reactors (SBCR) are widely employed for FTS processes. The scale-up of MTFBR is complicated by the ...
Numerical Study of the Controlled Droplet Breakup by Static Electric Fields inside a Microfluidic Flow-focusing Device
Y. Li, K. Nandakumar, M. Jain
Louisiana State Univeristy, Baton Rouge, LA, USA
Conventional passive microfluidic flow-focusing devices confront difficulties in controlling droplet sizes in dripping regime especially when the dispersed phase has a large viscosity. It is reported that external electric field can be used to manipulate the droplet breakup. In the present study, a computational fluid dynamics based level-set method coupled with perfect dielectric model has been ...
V. Runkana, S. Maheshwari, S. Cherlo, RSR Thavva
Tata Research Development and Design Centre, Tata Consultancy Services Ltd., Pune, Maharashtra, India
Polymer hydrogels are commonly used as carriers or vehicles for the controlled release of drugs, primarily because of their bio-compatibility and because rates of drug release can be controlled by manipulating polymer properties like molecular weight, cross linking ratio, etc. Drugs can be released for prolonged periods of time through polymer hydrogels [1, 2]. Sustained drug release may ...
J. Muñoz, R. Valencia, and C. Nieto 
 Semillero Termodinámica y Fluidos, Universidad Pontificia Bolivariana, Medellin, Antioquia, Colombia
 Grupo Automática y Diseño
 Instituto de Energía y Termodinámica, Mechanical Engineering Faculty, Universidad Pontificia Bolivariana, Medellin, Antioquia, Colombia
Genetic Algorithms (GA) have proved to be a complete and effective approach for solving optimization problems. This article presents the integration between COMSOL® and a GA optimization tool coded in MATLAB® for the optimization of two thermal systems: a constant area fin in 2D and a concentric heat exchanger in 2D. Analysis permitted us to achieve efficiencies of up to 90%. For the ...
H. White, L. Luo
Department of Chemistry, University of Utah, Salt Lake City, UT, USA
A characteristic feature of nanochannels is that surface properties (e.g., electrical charge) play a more significant role in the transport of fluid and electrolyte. Two oppositely directed flows (electroosmotic flow and pressure-driven flow) determine the flow profile at the nanopore orifice as well as electrolyte distribution. Once there are two electrolyte solutions with different ...
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 ...
A. Nanduri , P. L. Mills ,
 Department of Chemical and Natural Gas Engineering, Texas A&M University - Kingsville, Kingsville, TX, USA
In the early 1920’s, Gas-To-Liquids (GTL) and Coal-To-Liquids (CTL) technologies were developed to account for the depleting crude oil resources . During this period, Franz Fischer and Hans Tropsch developed a process to convert synthesis gas (syn gas), derived from coal gasification, to a wide range of high value-added products. This process later came to be known as Fischer-Tropsch (F-T) ...