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.

Design of MEMS based Polymer Microphone for Hearing Aid Application

V. S. Nagaraja[1], Ramanuja H. S.[1], Deepak K[1], S. L. Pinjare[1]
[1]Electronics and Communication Engineering, Nitte Meenakshi Institute of Technology, Bangalore, Karnataka, India

In this work, a MEMS based condenser microphone [1,2] using Polyimide as the diaphragm has been designed. The microphone structure has a backplate placed on top of the diaphragm. The backplate and the diaphragm are made up of polyimide. The two polyimide plates are separated by air gap which is achieved by using Aluminium as a sacrificial layer in between, which is etched away to create the air ...

Evaluation of Internal Resistance and Power Loss in Micro Thermoelectric Generators (µTEGs)

S. Seif[1], K. Cadien[1]
[1]Department of Chemical & Materials Engineering, University of Alberta, Edmonton, AB, Canada

One of the major challenges in designing µTEGs is to minimize power loss due to internal resistance (r) of Thermoelectric (TE) materials. To solve this problem we have performed simulation analysis and calculated the internal resistance of eight different TE materials. The internal resistances of these TE materials were then compared to the power generated across the copper electrode as seen in ...

Numerical Experiments on Deconvolution Applied to LES in the Modeling of Turbulent Flow

O. Toscanelli[1], V. Colla[1]
[1]Scuola Superiore S. Anna, Pisa, Italy

The Large Eddy Simulation is an important method to simulate turbulent flow. It does not produce a closed system of equations, to achieve this it is necessary to model the not-closed terms. The deconvolution can be used for this purpose. In this study some numerical experiments on this topic are performed with COMSOL Multiphysics®. The main objectives are to find an efficient way to implement ...

Empirical Model Dedicated to the Sensitivity Study of Acoustic Hydrogen Gas Sensors Using COMSOL Multiphysics®

A. Ndieguene[1], I. Kerroum[1], F. Domingue[1], A. Reinhardt[2]
[1]Laboratoire des Microsystèmes et de Télécommunications/Université du Québec à Trois-Rivières, Trois-Rivières, QC, Canada
[2]Laboratoire d’Électronique et des Technologies de l’Information, CEA, LETI Grenoble, France

Due to the increasing demand for hydrogen gas sensors for applications such as automation, transportation, or environmental monitoring, the need for sensitive and reliable sensors with a short response time is increasing. This paper presents an empirical model that studies the sensitivity of acoustic hydrogen gas sensors. A parametric study based on the variation of physical properties of ...

Water Quality Model for Brewster Lake

Z. Aljobeh[1], G. Argueta[1]
[1]Valparaiso University, Valparaiso, IN, USA

A numerical model was developed to make spatial and temporal predictions of the water quality for Brewster Lake, located in southwestern Michigan. The model considers the hydrodynamics of the lake, hydrologic conditions, physical, chemical and biochemical processes that take place in the lake, and nutrient loadings from the surrounding watershed. Physical, chemical, and biochemical data ...

An Assessment of the Suitability of the Body and Adult Head Coils for Transmission during Paediatric Magnetic Resonance Imaging

G.R. Cook[1], M.J. Graves[1], F.J. Robb[2], D.J. Lomas[1]
[1]Department of Radiology, University of Cambridge, Cambridge, United Kingdom
[2]General Electric Healthcare Coils, Aurora, Ohio, USA

MRI offers many advantages over other modalities and its lack of ionizing radiation is important for children, but can be limited by the radio-frequency (RF) coils available. This work calculates Specific Absorption Rate (SAR) and homogeneity of the RF transmit field (B1+) when imaging infants in adult coils. Two birdcage-type coils were loaded by a tissue model and their B1+ homogeneities ...

Modeling Mechanical Property Changes During Heating of Carrot Tissue - A Microscale Approach - new

S. Kadam[1], A. K. Datta[1]
[1]Department of Biological & Environmental Engineering, Cornell University, Ithaca, NY, USA

Turgor pressure loss and pectin degradation result in texture loss during cooking of plant based materials. To simulate texture loss, a simultaneous heat and moisture transfer, pectin degradation in the cell wall material and solid mechanical model was developed at the microscale using finite elements to predict the homogenized Young’s Modulus of the carrot tissue during heating. The model ...

Modeling of a Direct Methanol Fuel Cell

J. Drillet [1],
[1] DECHEMA-Forschungsinstitut, Frankfurt, Germany

This work aims at the modelling of a 5 cm^2 Direct Methanol Fuel Cell (DMFC) with mixed serial/parallel serpentine flow fields in terms of current/voltage behavior. One of the main challenge to overcome consists on lowering the so-called methanol cross over from the anode through the polymer membrane to the cathode that is responsible for mixed-potential formation at the cathode where both ...

Influence of Non-Newtonian Blood Viscosity on Wall Pressure in Right Coronary Arteries with Serial Stenoses

B. Liu [1]
[1] Monmouth University, West Long Branch, NJ, USA

Three dimensional mathematical models are developed to simulate the blood flows in patient specific right coronary arteries with two stenoses. Simulations are carried out with various flow parameters under physiological conditions. Both Newtonian and non-Newtonian blood viscosity models are applied in the simulations to examine the influence of non-Newtonian viscosity of blood on the wall ...


王威 [1], 周超 [1],
[1] 哈尔滨工业大学深圳研究生院,深圳,中国

微纳米马达是一种能将周围环境的能量转化为自身自主运动的新型智能仿生材料,其在药物的运输与释放,低维材料的合成以及软物质研究中有着重要的应用[1]。基于自电泳的双金属棒马达是研究时间最长的一类马达,它有着与自然界中类似的自组装和群体行为的特性[2]。但是其运动机理复杂且涉及到多个物理场的紧密耦合,这就为其进一步的研究和应用带来了一定的困难。 COMSOL Multiphysics® 可以方便地进行多物理场的模拟。图(1)展示了双金属棒的自电泳机理, 由于棒两端的化学反应造成了带电离子浓度的分布不均匀,进而产生自生电场驱动马达运动。其中传质过程、流体流动以及电场形成相互影响,环环相扣[3]。基于以上物理过程,我们对 COMSOL 中稀物质传递,静电和蠕动流接口进行了有效的耦合,从而实现了马达周围离子场,电场和流场的模拟(图2),在此基础之上,我们研究了马达的运动速度(图3) ...