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.

Simple Disk Piezo Transformer Based Oscillator - new

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 ...

Mathematical Model for Prediction of Transmission Loss for Clay Brick Walls

J. Ratnieks[1], A. Jakovics[1], J. Klavins[1]
[1]Laboratory for Modeling Technological and Environmental Processes, University of Latvia, Riga, Latvia

A 2D numerical model for determination of sound reduction index is set up in this work. Results are in good agreement in middle and high frequency range when using solid structure approximation. Results are compared with experiment.

Simulation Studies on the Design of a Helmholtz Resonator type Underwater Acoustic Sensor

Karthi Pradeep[1], G. Suresh[2], V. Natarajan[2],
[1]National Institute of Technology, Tiruchirappalli, Kerala, India
[2]Naval Physical & Oceanographic Laboratory (NPOL), Kochi, Kerala, India

A Helmholtz resonator type acoustic sensor has been designed using analytical method and finite element modeling software, COMSOL Multiphysics®. The acoustic sensor is an aluminium double frustum, hour glass, shaped with the resonator at the bottom and an acoustic horn above to amplify the incoming acoustic signal. The horn provides a broad amplification of the incoming acoustic signal while the ...

Modelling and Analysis of Acoustic Emissions and Structural Vibration in a Wind Turbine

B. Marmo, and B. Carruthers
Reactec Ltd., Edinburgh, United Kingdom

The onshore wind turbine industry must overcome many technical, commercial, and environmental difficulties. A significant element for planning consent is operational noise. Acoustic limits are strictly enforced and can lead to near-neighbour complaints as well as contractual disputes. Reactec have diagnosed, analysed and solved a problematic tonal resonance for a major wind turbine generator ...

Designing a Smart Skin with Fractal Geometry

S. Ni, C. Yang Koh, S. Kooi, and E. Thomas
Institute for Soldier Nanotechnologies
Dept. of Materials Science and Eng.
MIT
Cambridge, MA

Recently, the concepts of fractal geometry have been introduced into electromagnetic and plasmonic metamaterials. With their self-similarity, structures based on fractal geometry should exhibit multi-band character with high Q factors due to the scaling law. However, there exist few studies of phononic metamaterials having fractal geometry. COMSOL is used to investigate vector elastic and ...

On The Use of a Diffusion Equation Model for Sound Energy Flow Prediction in Acoustically Coupled Spaces

Y. Jing, and N. Xiang
Rensselaer Polytechnic Institute, Troy, NY, USA

This paper studies sound energy flows through an aperture across two coupled spaces using a diffusion equation model. The so-called double sloped sound energy decay is believed to be caused by the sound energy exchange through the aperture coupling the two rooms. The room diffusion equation is first solved by COMSOL, then the time dependent energy flow is visualized via COMSOL arrow plotting, ...

FEM Analysis of Flamelet Wrinkling in a Diffusion Flame - new

Y. Li[1], T.C. Lieuwen[2], J. Zhou[1], H. Cao[1]
[1]Zhengzhou University, Zhengzhou City, Henan Province, China
[2]Georgia Institute of Technology, Atlanta, GA

One can hardly get the exact analytic solution of a full time-dependent convection-diffusion equation, for describing the dynamics of a non-premixed flamelet. The analytic solution of the linearized form with such a model was studied by MATLAB®. And also, a numerical computation was made with the linearization model in COMSOL Multiphysics® software, to provide a perfect accordance with the ...

Influence of Thermal Conductivity and Plasma Pressure on Temperature Distribution and Acoustical Eigenfrequencies of High-Intensity Discharge Lamps

J. Schwieger[1], B. Baumann[1], M. Wolff[1], F. Manders[2], J. Suijker[2]
[1]Heinrich-Blasius-Institute of Physical Technologies, Hamburg University of Applied Sciences, Hamburg, Germany
[2]Philips Lighting, Turnhout, Belgium

High-intensity discharge (HID) lamps are energy-efficient light sources with excellent color qualities. A three-dimensional model of a low-wattage lamp, which includes plasma, electrodes, and burner walls, was developed in COMSOL Multiphysics®. Most parameters appearing in the coupled differential equations of the model, such as viscosity, thermal and electrical conductivity are temperature ...

Acoustic and Flow Analysis to Reduce Boiler Hum - new

Th. B. J. Campmans[1],
[1]LBPSIGHT, Nieuwegein, The Netherlands

A installation caused severe hum, with 30 Hz as dominant frequency, causing serious annoyance. The acoustic study showed resonances around 30 Hz. Poor flow conditions existed at the inlet and outlet of the forced draft fan. Flow patterns were studied using CFD. Both the inlet and outlet contained large vortices, causing the strong hum. Changes in the design were studied. The finally changes ...

Nondestructive Testing of Composites Using Model Based Design

E. Nesvijski[1]
[1]ACOUSTICS@MBD CONSULTANTS, LLC, Westborough, MA, USA

There is a practical interest among composite materials manufacturers to high-speed accurate non-destructive evaluation (NDE) technology for voids inspection when these voids are natural components of such complex structures like resin insulated layer of double-sided copper-clad laminates. Model based design (MBD) of NDE system is one of principal solutions for voids inspection in such ...