In questa sezione troverete i lavori presentati alle Conferenze mondiali COMSOL. Le presentazioni descrivono ricerche e prodotti innovativi progettati con COMSOL Multiphysics da colleghi di tutto il mondo. I temi delle ricerche presentate abbracciano un'ampia gamma di settori produttivi e aree applicative, in ambito elettrico, meccanico, fluidodinamico e chimico. Lo strumento di Ricerca Rapida vi permetterà di trovare le presentazioni che si riferiscono all'area di vostro interesse.

Steps for the Optimization of Pipe and Tubing Extrusion Dies

J.R. Puentes[1], T.A. Osswald[1], S. Schick[2], J. Berg[2]
[1]Polymer Engineering Center, University of Wisconsin, Madison, WI, USA
[2]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 ...

Modeling Flow and Deformation during Hot Air Puffing of Single Rice Kernels

T. Gulati[1], A. Datta[1]
[1]Cornell University, Ithaca, NY, USA

When rice is subjected to intense heating, it results in rapid evaporation of liquid water to vapor. As a consequence, large pressures are generated within the kernel in a span of 15s resulting in large volume changes causing the kernel to puff rapidly. Under suitable conditions, the ratio of initial volume to volume after puffing could be as high as 10. Rice puffing process is a complex ...

Two-Phase Flow Models of Gas Generation and Transport in Geological Formations

O. Silva [1]
[1] 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 ...

Investigation of Reverse ElectroDialysis Units by Multi-Physical Modelling

L. Gurreri [1], F. Santoro [1], G. Battaglia [1], A. Cipollina [1], A. Tamburini [1], G. Micale [1], M. Ciofalo [1],
[1] 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, ...

激光熔覆过程中的传热传质研究

甘政涛 [1],
[1] 中国科学院力学研究所,北京,中国

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) ...

Modeling Proton Transport in Hydrophobic Polymeric Electrolytes

M. Andrews[1]
[1]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 ...

Boundary Value Effects on Migration Patterns in Hydraulically Fractured Shale Formations - new

T. Aseeperi[1]
[1]Department of Chemical Engineering, University of Arkansas, Fayetteville, AR, USA

During the hydraulic fracturing process, there can be possible re-activation of closed/sealed faults and natural fractures in the formation, which may lead to changes in the boundary conditions of the reservoir. While study models of shale gas formations have utilized the concept of a closed reservoir in order to optimize the production of gas in the well-bore, this assumption cannot be adopted ...

Modeling of Fluid Flow and Heat Transfer During a Steam-Thermolysis Process for Recycling Carbon Fiber Reinforced Polymer

A. Oliveira Nunes[1], Y. Soudais[1], R. Barna[1], A. Bounacer[1], Y. Yang[1]
[1]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 ...

Benchmarking Tailored Formulations of Multiphase Flow in Porous Media

Á. Sainz [1,2], A. Nardi [1], E. Abarca [1], F. Grandía [1]
[1] Amphos 21 Consulting S.L., Barcelona, Spain
[2] Université Toulouse III - Paul Sabatier, Toulouse, France

Nowadays, gas and nuclear waste storage, shale gas and EOR exploitation rise the need to understand and predict the fate of multiphase flows in the underground. Various formulations for multiphase flow arise from different linear combinations of governing equations and choice of associated unknowns. Each formulation has its own benefits and drawbacks; and the optimal may vary depending on the ...

Simulating Hydraulic Fracturing and Contaminant Transport with MATLAB® and COMSOL Multiphysics® Software

D. W. Pepper [1], E. Nabizadeh [1], J. Waters [2],
[1] University of Nevada Las Vegas, Las Vegas, NV, USA
[2] 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 ...