Technical Papers and Presentations

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.

Modeling Low Frequency Axial Fluid Acoustic Modes in Continuous Loop Piping Systems

E. Gutierrez-Miravete[1], E.R. Marderness[2]
[1]Rensselaer Polytechnic Institute, Hartford, CT, USA
[2]General Dynamics-Electric Boat, Groton, CT, USA

Industrial fluid systems often involve continuous piping loops. These systems consist of varying lengths of pipes and hoses connecting multiple components together. Fluid resonances can detrimentally affect the operation of fluid systems and components. This work used COMSOL to investigate the frequency and mode shapes of axial fluid resonances within a system of piping and components that form ...

COMSOL Multiphysics® Simulation of Ultrasonic Energy in Cleaning Tanks

L. Zhong[1]
[1]Seagate Technology, Bloomington, MN, USA

Ultrasonic based cleaning process, widely used in various industries, mainly utilizes the cavitation effect to achieve contamination removal. For a given set of ultrasonic tank parameters, such as cleaning fluid, temperature, frequency etc, the cavitation effect is largely impacted by the amount of ultrasonic energy. Determining optimal ultrasonic energy level often becomes the key to the ...

Simple Disk Piezo Transformer Based Oscillator

J. P. Sandoz[1], J. M. Kissling[1]
[1]Institute of Applied Microtechnology, La Chaux-de-Fonds, HE‐ARC, Switzerland

In this contribution we present a COMSOL Multiphysics® example of a disk piezoelectric ceramic transformer (D-PT) coupled with a bipolar NPN transistor to form an auto-oscillator. The comparison between the simulations and the measurements made on our prototype are found to be in good agreement. Having at our disposal a large number of homogenously poled disks, we decided to build and to ...

Guided Wave in Engineering Structures Using Non-Contact Electromagnetic Acoustic Transducers: A Numerical Approach for the Technique Optimisation

S. Soua[1], A. Raude[1], and T-H. Gan[1]
[1]NDT Technology Group, TWI Ltd, Cambridge, United Kingdom

There are over 10 million kilometers of pipes and pipelines around the world that carry hazardous fluids and gases. Fluids include oil, oil products, chemicals such as solvents, caustics, acids, corrosives and combustibles often at high pressure and temperature. These pipes are susceptible to corrosion if they are not protected properly by the environment or the contents. Inspection of pipes is ...

Sound Attenuation by Hearing Aid Earmold Tubing

M. Herring Jensen
Widex A/S, Vaerloese, Denmark

In this study we model the sound attenuation properties of a hearing aid earmold tube. The model includes thermoviscous acoustic effects and it couples structural vibrations to the external acoustic field. Moreover, the finite element domain is coupled at two boundaries with an electroacoustic model of a hearing aid and an acoustic 2-cc coupler.

Optimal Design of Slit Resonators for Acoustic Normal Mode Control in Rectangular Rooms

S. Floody[1], R. Venegas[2], and F. Leighton[3]
[1]Universidad de Chile, Facultad de Artes, Departamento de Música y Sonología, Licenciatura en Sonido, Santiago, Chile
[2]University of Salford, Acoustics Research Centre, Salford, UK
[3]Universidad Tecnológica de Chile Inacap, Sede Pérez Rosales, Santiago, Chile

The present article presents a method to redistribute the acoustic modes of a rectangular enclosure in the low frequency range using slit resonators. The objective of the present work is to compare different strategies of optimal design in order to determine the dimensions of the resonators. The method of the finite elements will be used to model the acoustic physical behavior of the room. In ...

Application of Transfer Matrix Method in Acoustics

G. Campa, and S.M. Camporeale
Politecnico di Bari, Bari, Italy

The Transfer Matrix method in the Acoustics Module of COMSOL Multiphysics is used when the whole system can be represented into a sequence of subsystems that interact only with adjacent subsystems. This method is frequently used in mathematics and, particularly, in acoustics. The application of the present method is really useful, because it permits to break the total system into a network of ...

Acoustic-Structure Interaction Modeling of Piezoelectric Transducer in Fluid Medium

V.M. Acosta[1], E. Riera[1], G. Rodriguez[1], A. Pinto[1], A. Cardoni[2], J.A. Gallego-Juárez[1]
[1]Power Ultrasonics Group, CSIC, Serrano, Madrid, Spain
[2]Pusonics, Arganda del Rey, Madrid, Spain

This work describes the design methodology and development of piezoelectric transducers for applications in fluids with COMSOL_Multiphysics. In these linear models for the acoustic-structure interaction approximate numerical solutions have been obtained. In order to perform the calculations, simplifications are only valid for low-power sound waves. Numerical modeling of piezoelectric transducers ...

Temperature Gradients Controlled Broadband Acoustic Omnidirectional Absorber - new

F. Qian[1], L. Quan[1], X. Liu[1]
[1]Institute of Acoustics and School of Physics, Nanjing University, Nanjing, China

Previous research into acoustic omnidirectional absorber (AOA) has shown the feasibility of forming acoustic black hole to guide the incident wave into the central absorptive cavity. However, major restrictions to practical applications exist due to complexity of designing metamaterials and unchangeable working states. Here, we propose two cylindrical, two-dimensional AOA schemes based on ...

A Study of FEMLAB for Modeling High Frequency Ultrasound Scattering by Spherical Objects

Falou, O.1, Kumaradas, J.C.2, Kolios, M.C.3 1 Dept. of Electrical and Computer Engineering, Ryerson University, ON, Canada
2 Dept. of Electrical and Computer Engineering & Dept. of Physics, Ryerson University, ON, Canada
3 Dept. of Physics, Ryerson University, ON, Canada

Analytical solutions to the problem of wave scattering from three dimensional structures such as spheres have been studied extensively in the past. However, these solutions are not flexible enough to be extended to wave scattering from complex geometries. We have developed a finite element model of acoustic wave propagation through spherical structures to solve the problem of highfrequency (20 ...

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