Here you will find presentations given at COMSOL Conferences around the globe. The presentations explore the innovative research and products designed by your peers using COMSOL Multiphysics. Research topics span a wide array of industries and application areas, including the electrical, mechanical, fluid, and chemical disciplines. Use the Quick Search to find presentations pertaining to your application area.

Analysis of a Prototype MRI Hybrid Birdcage RF Coil with Uncertainty Quantification (*)

J. T. Fong [1],
[1] National Institute of Standards & Technology, Gaithersbug, MD, USA

1. INTRODUCTION. In a magnetic resonance imaging (MRI) system (see Fig. 1), it is necessary to excite the nuclei of a patient into coherent precession for imaging. This requires coupling between the nuclei and a source of radio frequency (RF) power (the transmitter). To receive a meaningful signal, one also needs to couple the nuclei to an external circuitry (the receiver). These two ...

Enhancing Fluorescence of Diamond Color Centers near Gold Nanorods via Geometry Optimization

M. Csete [1], A. Szenes [1], L. Zs. Szabó [1], G. Szabó [1], T. Csendes [2], B. Bánhelyi [2],
[1] Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary
[2] Institute of Informatics, University of Szeged, Szeged, Hungary

Detecting light emitted by fluorescent molecules with resolution down to single photon is an important problem in various fields of sciences and applications, such as solid-state physics, quantum information processing and medicine. The detection probability can be improved via enhancement of excitation and emission. Enhancement both of these processes can be reached by localized surface plasmon ...

Chemical Reaction Under Highly Precise Microwave Irradiation

S. Fujii[1], Y. Wada[2]
[1]Chiba University, Chiba, Japan
[2]Tokyo Institute of Technology, Tokyo, Japan

Chemical reactions conducted under microwave irradiation have high reaction rates and high selectivity, but these reaction rates are not always reproducible. To achieve reproducibility, a solid-state microwave source with an ultra precise oscillator, high power amplifier module (HPA), and elliptical applicator is developed. This HPA has up to 141 W average power and generates pure 2.45-GHz sine ...

Microwave Radiation to Cure Cork Stoppers Using a Conventional Turntable Configuration

D. Fidalgo[1], J. Monteiro[1], L. Costa[1]
[1]I3N and Physics Department, University of Aveiro, Aveiro, Portugal

This work presents an alternative method for curing cork stoppers based on microwave radiation, which is energetically more efficient, where it is possible to accelerate the reaction rate and therefore reduce the cure time comparatively with conventional curing methods. The microwave energy is directly introduced in the volume of the dielectric material and as a consequence, the quality of the ...

Launcher Design for Chemical Looping Combustion

F. Gao[1], D.W. Greve[1]
[1]Carnegie Mellon University, Pittsburgh, PA, USA

We report here on the use of the COMSOL emw (electromagnetic waves) module in the design of a microwave launcher. This launcher is to be used in a microwave Doppler sensor that is incorporated into a chemical looping combustion system. The launcher is designed in two steps. First, we determine the best mode for launching a wave into air from an overmoded cylindrical waveguide. he TE11 mode is ...

Three-Dimensional (3D) Modeling of Heat and Mass Transfer during Microwave Drying of Potatoes

H. Zhu[1][2], T. Gulati[2], A. K. Datta[2], K. Huang[1]
[1]Institute of Applied Electromagnetics, Sichuan University, Chengdu, China
[2]Department of Biological and Environment Engineering, Cornell University, Ithaca, NY, USA

Microwave drying of fruits and vegetables in a domestic oven has been found to result in large textural changes in the product such as puffing, crack formation and even burning due to the inhomogeneous heating of the microwaves. Microwave drying of potatoes is a complex interplay of mass, momentum and energy transport. Three phases are considered in the system: solid (skeleton), liquid (water) ...

Multiphysics Analysis of RF Cavities for Particle Accelerators: Perspective and Overview

M. Awida [1],
[1] Fermi National Particle Accelerator Laboratory, Warrenville, IL, USA

Particle accelerator technology evolves gradually towards improving reliability and efficiency of the accelerator machines, which would reduce their cost for current applications and even make them more accessible to new industrial applications. RF cavities are utilized in particle accelerator machines to propel the particle beam by properly coupling the energy from RF sources to the particle ...

Design of a Microreactor for Microwave Organic Synthesis through Microwave Heating Simulations

W. H. Lee[1], K. Jensen[1]
[1]Massachusetts Institute of Technology, Cambridge, MA, USA

We will present the issues of a microreactor setup designed for microwave organic synthesis and demonstrate how COMSOL Multiphysics® is used to understand the mechanism of microwave heating and improve the microreactor design. The RF Module was used for the electromagnetics and solid heat transfer simulations of a CEM Discover microwave unit, while the Heat Transfer and CFD Modules were used the ...

Liquid Crystal Based Terahertz Metamaterial Absorbers

Wang Lei [1],
[1] Nanjing University of Posts and Telecommunications, Nanjing, China

Metamaterial-based absorbers play a significant role in applications ranging from energy harvesting and thermal emitters to sensors and imaging devices. The middle dielectric layer of conventional metamaterial absorbers has always been solid. Researchers could not detect the near field distribution in this layer or utilize it effectively. Here, we use anisotropic liquid crystal as the dielectric ...

螺旋推进器对提高微波辅助生物柴油生产效率的作用

叶菁华 [1], 朱铧丞 [1]
[1] 四川大学,成都,中国

微波辅助生物柴油生产越来越受到了人们的关注,但是,微波的不均匀加热也影响了微波辅助生物柴油的大规模生产。研究表明,连续流微波加热器可以有效地解决微波辅助生物柴油的批量生产问题[1],螺旋推进器也可以改善加热均匀性,于是仿真带有螺旋推进器的连续流微波加热器的生物柴油生产过程,有利于优化连续流微波加热器的设计,对提高微波辅助生物柴油生产效率有重要的意义。 本文使用了电磁场、旋转机械流、流体传热和化学反应接口。电磁场中的介电系数是关于温度和物质浓度的函数,流体的热参量由流体各组分的质量比等效所得[2]。计算采用步进求解的方法,先在频域求解电磁场,所得的耗散功率代入流体传热,再将求解得到的温度和浓度用于更新介电系数,如此类推直至计算时间结束。 图1为有无螺旋推进器的连续流微波加热器的纵截面温度分布图,可见由于螺旋推进器的搅拌作用,流体的温度均匀性得到了很好的提高 ...