A. Mallco Carpio , M. Cortes Carmona ,
 University of Antofagasta, Antofagasta Energy Center, Antofagasta, Chile
One of the most noticeable effects in loss of performance and capacity of thermal systems is produced by altitude. This causes that the density of a compressible fluid and the atmospheric pressure are considerably reduced, causing a decrease in electrical power and thermal systems. Given this, the packages of lithium ion batteries that use forced cooling by a compressible fluid, are directly ...
可穿戴设备是近几年发展最快的电子产品之一，但是目前电池寿命仍然不够长、换电池代价高等问题制约进一步发展。为解决该问题，本文提出一种可拉伸式压电振动能量采集器，通过转化肢体运动的能量直接为设备的供能。该器件由柔性衬底、压电铁磁性悬臂梁以及磁铁组成。当衬底被拉伸，悬臂梁从磁铁上分离，进入高频振动发电状态；当衬底从拉伸状态恢复，悬臂梁被磁铁吸引，再次高频发电。本工作先建立器件 3D 模型，用 COMSOL 结构力学得到的前三阶模态阵型，并和解析计算结果进行对比，阵型函数很相近。采用压电设备和 AC/DC 电路模块进行多物理场耦合：在特征值研究中，分析两次高频振动发电的固有频率和模态；在瞬态研究中，分析器件位移、电压等时域结果，采用对电压求积分的后处理办法计算平均发电效率；还对不同 AC/DC 电阻负载进行参数扫描，找到匹配电阻最大化发电效率。同时采用 AC/DC 无电流磁场模块 ...
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.
INFN/LNL, Laboratori Nazionali di Legnaro, Legnaro, Italy
Many scientific instruments are based on high vacuum equipment with a gas pressure maintained in the order of 1 Pa or below. The gas flow in the low pressure limit, called the molecular flow regime, is a case of transport with zero viscosity. The ability to solve an integral equation on the boundary with finite elements methods allows us to find the gas densities and flows in the ...
Extraction of Phenolic Compound from Grape Fruit. A Comparison Between a 3D FEM Model and Experimental Results
E. Madieta, I. Zouid, R. Siret, and F. Jourjon
Laboratoire GRAPPE, ESA, Angers, France
Fresh fruits and vegetables are gaining importance in the human diet because they contain many beneficial compounds. Among these compounds, phenols are of vital importance due to their antioxidant properties. It is well evident from previous researches that the skin of red grapes is considered a good source of phenols. The aim of this work is to simulate the extraction procedure of phenols in ...
A. Nyman, M. Behm, and G. Lindbergh
Applied Electrochemistry, School of Chemical Science and Engineering, Royal Institute of Technology Stockholm, Sweden
Modeling of mass transport is an important step in evaluating lithium-ion battery electrolytes and understanding cell performance. For high-power applications, concentration gradients in the electrolyte lead to limiting currents, which limit the power-density of the battery. The model has been used for determining a complete set of transport and thermodynamic properties for LiPF6 dissolved in an ...
Kurt Lund Consulting, Del Mar, California, USA
A kernel of grain is modeled as an isothermal sphere, with descriptive differential equations scaled or rendered into non-dimensional form, where moisture transfer is governed by internal diffusivity, not by surface conditions. The time dependent problem is solved with COMSOL and the average non-dimensional moisture content and its time-rate of change are obtained; by regression, these numerical ...
L. Braci, S. Ognier, and S. Cavadias
Laboratoire de Génie des Procédés Plasmas et Traitements de Surfaces, Ecole Nationale Supérieure de Chimie de Paris, University Pierre et Marie Curie, Paris, France
Non-thermal plasma, generated in atmospheric pressure discharges, has been investigated in our laboratory in order to treat highly diluted (300 ppm to 1000 ppm) volatile pollutant. The collision of electrons created in the discharge with atmospheric air, leads to the formation of reactive species that can totally or partially oxidize the pollutants at near ambient temperature. The purpose of the ...
S. De Paolis, F. Lionetto, and A. Maffezzoli
Department of Innovation Engineering, University of Salento, Lecce, Italy
Finite element analysis has been used to model the ultrasonic wave propagation both in a custom made transducer and in the tested polymer sample. The model consists of acoustic (passive elements) and electroacoustic (active elements) transmission lines. The simulation of the acoustic propagation accounts for the interaction between the transducer and the materials in the buffer rods, and the ...
P. Lamy-Bracq and C. Coulouarn
Nexter Munitions, Tarbes, France
A solidification process of casting explosives in shell is studied in this paper. An enthalpy method approach is used to model the solidification process. Both the thermal and mechanical effects are taken into account. An ALE (Arbitrary Lagrangian-Eulerian) method is used to represent the physical deformation due to solidification. Results from the model are verified against experimental ...