J.R. Puentes, T.A. Osswald, S. Schick, J. Berg
Polymer Engineering Center, University of Wisconsin, Madison, WI, USA
TEEL Plastics, Baraboo, WI, USA
The extrusion of polyolefin pipes suffers degradation due to mechanical design problems of the extrusion die that is commonly used. This study uses numerical and computational approaches to detect problematic areas in the die geometry. Simulations show that in the conventional die there are areas of stagnation and recirculation of the melt flow, resulting in greater residence times, one of the ...
O. Silva 
 Amphos 21 Consulting S.L. - iMaGe Consortium, Barcelona, Spain
Gas generation and transport through porous media is a process common to many field applications such as radioactive waste and underground gas storage. In these operations, the gas phase evolution depends on the thermodynamic conditions at depth, the properties of the fluids (density, viscosity, surface tension) and the geological formation (permeability, porosity, retention curve), as well as ...
L. Gurreri , F. Santoro , G. Battaglia , A. Cipollina , A. Tamburini , G. Micale , M. Ciofalo ,
 Dipartimento di Ingegneria Chimica, Gestionale, Informatica, Meccanica (DICGIM), Università degli Studi di Palermo (UNIPA), Palermo, Italy
Salinity gradient represents an interesting renewable energy source. Reverse ElectroDialysis (RED) is an ion exchange membrane-based process that convert directly the salinity gradient energy into electric current. Thereby, two solutions at different concentrations are fed into two series of alternated channels. As various physical phenomena occur in RED units and affect the process performance, ...
Caribbean Industrial Research Institute, Calibration Laboratory, University of the West Indies, St. Augustine, Trinidad and Tobago
The Polymer Electrolyte Membrane fuel cell is one of the most promising green technologies for addressing portable, as well as transportation power needs. However, the science behind the fuel cell, in many regards, is still an enigma, and even more so, with the vast numbers of novel materials created annually; designed to offset issues related to durability, conductivity, cost- effectiveness and ...
基于 Level-Set 界面跟踪方法建立了激光熔覆过程的三维瞬态数值模型，研究了瞬态熔化和凝固过程中传热传质的演化规律。该模型使用 Level-Set 方法跟踪熔池气/液界面，采用焓－多孔度（enthalpy-porosity）方法得到了固/液界面之间的糊状区，并考虑了质量添加、材料熔化/凝固、热毛细效应（Marangoni效应）、浮力效应、活性元素质量传输等对熔池流动和界面的影响。通过该模型，具体分析了质量添加、力和界面平衡条件对熔池气/液界面的影响，以及由熔池温度/浓度分布引起的热毛细效应、金属材料的熔/凝过程和熔池流动形式对熔池固/液界面的影响。结果表明：熔池的气/液界面主要由力平衡条件决定，截面近似为圆弧型，其尺寸与单位时间的质量添加量相关。熔池的固/液形态由于熔池的表面温度梯度和表面活性元素含量共同引起的熔池流动方向和速度的变化，出现三种不同的类型，分别为下凹型（熔池内流） ...
Simulating Hydraulic Fracturing and Contaminant Transport with MATLAB® and COMSOL Multiphysics® Software
D. W. Pepper , E. Nabizadeh , J. Waters ,
 University of Nevada Las Vegas, Las Vegas, NV, USA
 Los Alamos National Laboratory, Los Alamos, NM, USA
Hydraulic fracturing, or fracking, is a technique used to extract oil and gas in shale rock. A mixture of water, sand, and chemicals are pumped into the well at high pressures to keep the fissures open, which allows the gas to flow. Although intermediate casings are inserted into the well to prevent the fracturing fluid or oil or gas from entering the water supply at the ground water layer ...
E. Holzbecher ,
 German University of Technology in Oman (GUtech), Halban, Oman
A model for CO2 storage is presented. It is shown that the system is highly dynamic, i.e. results depend strongly on parameter disturbances and numerical features. However, a series of scenario calculations shows that there are invariants, most important: the duration of the early convection phase with high mass transfer rates.
Modeling of Fluid Flow and Heat Transfer During a Steam-Thermolysis Process for Recycling Carbon Fiber Reinforced Polymer
A. Oliveira Nunes, Y. Soudais, R. Barna, A. Bounacer, Y. Yang
Centre RAPSODEE - Ecole des Mines d'Albi, Albi, France
Different types of technologies to recycle carbon fiber reinforced polymer (CFRP) waste have been studied, for example: pyrolysis, solvolysis and steam-thermolysis. The steam-thermolysis is a process that combines pyrolysis and superheated steam at atmospheric pressure to decompose the organic matrix of the composite. The waste is introduced into a bench-scale reactor heated at high temperatures ...
T. Schaffner , A. Hartmaier 
 ThyssenKrupp, Duisburg, Germany
 Ruhr-Universität Bochum, Bochum, Germany
The prediction of material damage induced by hydrogen transport mechanisms is a major challenge for the development of new steel concepts. Especially the ultra-high strength steel concepts (UHSS), like dual phase and martensitic steels, can exhibit a higher vulnerability to hydrogen induced damage. The main reason for this is the complex microstructure, including a large number of several ...
O. Akanji, and A. Kolesnikov
Department of Chemical & Metallurgical Engineering
Tshwane University of Technolgy
Pretoria, South Africa
In this work, a 2D dynamic simulation for a portion of metal hydride based hydrogen storage tank was performed using computational software COMSOL 4.0a Multiphysics. The software is used to simulate the diffusion and heating of hydrogen in both radial and axial directions. The model consists of a system of partial differential equations (PDE) describing two dimensional heat and mass transfer of ...