Study of Fracture Parameter for Curved Cracked Bimodular Flexural Specimen Using COMSOL Multiphysics® Software
A. Bhushan , S.K. Panda ,
Indian Institute of Technology (BHU) Varanasi, Uttar Pradesh, India
The formulation of bimodular stress field is based on stress dependent elasticity and the simulations have been carried out using commercial finite element software COMSOL Multiphysics® software. The complexity of the problem is enhanced due to adding bimodular stress field in the evaluation of complex J-integral ( ˆ F J ) for curve cracked geometry subjected to flexural loading. The complex J ...
A. Landázuri , V. Benavides ,
 Chemical Engineering Department, GICAS Group, Universidad San Francisco de Quito, Quito, Ecuador
A three-dimensional model of particle saltation using computational fluid dynamics (CFD) is presented. This model domain reproduces a flat and irregular terrain with uniform roughness. The domain extends 2 m in X, 0.5 m in Y and 0.5 in Z for both cases. The model includes the motion of particles due to shear force, gravity, drag and the effect of turbulence as a result of the retardation of the ...
J. S. Crompton , J. Thomas , K. Koppenhoefer ,
 AltaSim Technologies, Columbus, OH, USA
Necrosis of human tissue can typically be obtained by exposure to temperatures below 40°C or above +50°C. However, inherent variability in tissue properties, the complexity of tissue response and dissipation of thermal energy by local perfusion or blood flow can make the development of routine, predictable in-vivo approaches to produce necrosis difficult. Although a number of thermal ablation ...
硅通孔在实现高级集成系统中起着至关重要的作用，但是其发展受到多物理场耦合效应的极大阻碍。硅通孔的多物理场耦合过程非常复杂，热场分布、电磁场分布及结构分布是相关联、相互作用的。针对硅通孔的多物理场耦合问题，本文开展了硅通孔多物理场仿真分析研究。结合国内外在硅通孔多物理场本质研究的基础上，从多物理场耦合理论出发，建立单个硅通孔的多物理场分析模型。通过运用 COMSOL Multiphysics 软件进行建模如图 1，在稳态下选择相应的焦耳热和热膨胀接口进行仿真如图 2，经影响分析确定了硅通孔的一些结构参数，如二氧化硅隔层厚度取 0.8um，硅基质厚度取 5.5um，硅通孔高度取 83.6um。最后，选择焦耳热接口进行瞬态仿真，研究了电压周期函数的幅值大小和占空比对硅通孔温度变化的影响关系。数值结果表明，随着幅值的增大，最终稳定后，温度的波动范围和最高温度都将增大如图 3；随着占空比不断增大 ...
王永超 , 葛进 ,
海上石油泄漏不仅造成资源的浪费，还长期威胁着脆弱的生态系统。然而浮油具有面积大、油层薄、粘度大的特点，难以采用传统的技术和材料来有效地处理。作者利用石墨烯海绵疏水亲油、导电的特点，设计了一种原位加热的方法，有效地较低了原油的粘度，增大了油在海棉里的扩散系数，在解决快速吸附高粘度原油这一世界性难题方面取得了突破性进展。 在这个研究工作中，作者发现很难在实验上获得此方法的能量消耗情况，为了回答这个问题，作者应用 COMSOL® 软件，模拟了石墨烯海绵加热吸油的热传导过程。运用电流模块，模拟石墨烯泡沫通电加热升温的过程，用热传导模块模拟热量通过石墨烯泡沫传递到油、水、空气的过程，并且对电极分布方式进行了优化。作者统计了热量散失在各个组分的比例，结果表明，只有少部分的热量散失在水中，比起传统的电阻丝加热浮油的方法，能耗减少了 65%。
M. Gobbert, and S. Yang
Department of Mathematics and Statistics, University of Maryland, Baltimore, MD, USA
The convergence order of finite elements is related to the polynomial order of the basis functions used on each element, with higher order polynomials yielding better convergence orders. However, two issues can prevent this convergence order from being achieved: the lack of regularity of the PDE solution and the poor approximation of curved boundaries by polygonal meshes. We show studies for ...
Massachusetts Institute of Technology, Cambridge, MA, USA
Markus Zahn received all his education at MIT, was a professor in the Department of Electrical Engineering at the University of Florida, Gainesville from 1970-1980, and then joined the MIT Department of Electrical Engineering and Computer Science faculty in 1980. He works in the Laboratory for Eelectromagnetic and Eelectronic Systems, in the MIT High Voltage Research Laboratory, is the Director ...
E. Zanchini, and T. Terlizzese
Dipartimento di Ingegneria Energetica, Nucleare e del Controllo Ambientale, Università di Bologna, Bologna, Italy
The results of two thermal response tests recently performed on two vertical borehole heat exchangers (BHEs) are presented. The BHEs have the same cross section and a depth of 100 m and 120 m respectively. The evaluation of the thermal properties of the ground and grout are performed by a finite-element simulation method, developed through the software package COMSOL Multiphysics 3.4.
D. Scandura, G. Currenti, and C. Del Negro
Istituto Nazionale di Geofisica e Vulcanologia Sezione di Catania, Catania, Italy
In volcanic areas, the presence of heterogeneous materials and high temperatures affect the rheological behaviour of the Earth's crust that calls for considering the anelastic properties of the medium surrounding the magmatic sources. A thermo-mechanical numerical model is performed for evaluating the temperature dependency of the elasto-plastic solution. Both temperature distributions and ...
Fundamental Three Dimensional Modeling and Parameter Estimation of a Diesel Oxidation Catalyst for Heavy Duty Trucks
A. Holmqvist and C.U.I. Odenbrand
Department of Chemical Engineering, Faculty of Engineering, LTH, Lund University, Lund, Sweden
Mathematical optimization can be used as a computational engine to generate the best solution for a given problem in a systematic and efficient way. In the context of monolithic converter systems, the parameter estimation problem (or inverse problem) is solved using Partial Differential Equations (PDE)-based models of the physical system coupled with an optimization algorithm. These problems are ...