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.

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 ...

Numerical Simulation of Phonon Dispersion Relations for Phononic Crystals

G. Zhu[1], E.M. Dede[1]
[1]Toyota Research Institute of North America, Ann Arbor, MI, USA

In previous work, a two-dimensional (2D) model was carried out to simulate the phononic band structure of a phononic crystal with square lattice structure, but this model did not account for the out-of-plane phonon dispersions [1]. In fact, for 2D films used for coating materials, it is more interesting to understand their cross-plane properties. In this work, the phonon dispersion relation of ...

Parametric Simulation of PZT Diameter to Hole Ratio for Optimized Membrane Displacement

A. Arevalo [1], D. Castro [1], D. Conchouso [1], I. G. Foulds [2]
[1] Computer, Electrical and Mathematical Sciences and Engineering (CEMSE), King Abdullah University of Science and Technology (KAUST), Saudi Arabia
[2] The University of British Columbia, School of Engineering, Okanagan Campus, Saudi Arabia

For our simulation we used the Piezoelectric Devices interface. The structure was set with (clamped) fix constraint boundaries to both ends. The bottom electrode was set to be the ground for the electrostatic physics and the top electrode was set to be a Terminal with potential of 10V. A parametric sweep study was set to change the geometry, the parameters to change was the hole diameter (Holed) ...

Finite Element Modeling of Ultrasonic Transducers for Polymer Characterization

S. De Paolis[1], F. Lionetto[1], and A. Maffezzoli[1]

[1]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 ...

Lamb Waves in Fluid-Loaded Plates

T. Kaufmann[1], F. Kassubek[1], D. Pape [1], M. Lenner[1]
[1]ABB Corporate Research, Baden-Dättwil, Switzerland

Lamb waves are elastic waves propagating in free solid plates. In the case of plates loaded with a fluid, the equations describing these waves have to be modified to include the effects of the fluid. In our work we have tackled this problem using COMSOL Multiphysics®. We have used the two-dimensional plane strain model of the solid mechanics interface to calculate the eigenmodes of the coupled ...

Design of Electroacoustic Absorbers Using PID Control

H. Lissek, R. Boulandet, and M. Maugard
Ecole Polytechnique Federale de Lausanne
Lausanne, Switzerland

An \"electroacoustic absorber\" is a loudspeaker, used as an absorber of sound, which acoustic impedance can be varied by electrical means. This can be achieved either by plugging passive shunt electric networks at the loudspeaker terminals (“shunt loudspeakers”) or by feeding back the loudspeaker with a voltage proportional to acoustic quantities, such as sound pressure and diaphragm normal ...

Mean Flow Augmented Acoustics in Rocket Systems - new

S. Fischbach[1]
[1]NASA Marshall Space Flight Center / Jacobs ESSSA Group, Huntsville, AL, USA

Combustion instability in solid rocket motors and liquid engines has long been a subject of concern. Recent advances in energy based modeling of combustion instabilities require accurate determination of acoustic frequencies and mode-shapes. Of particular interest is the acoustic mean flow interactions within the converging section of a rocket nozzle, where gradients of pressure, density, and ...

Comsol’s New Thermoviscous Interface and Computationally Efficient Alternative Formulations for FEM

W. R. Kampinga[1], and Y. H. Wijnant[2]
[1]Reden, Hengelo, Netherlands
[2]University of Twente, Enschede, Netherlands

Three efficient alternatives to the model in COMSOL’s thermoacoustics interface are presented. The higher efficiency of these models are explained from theory and are demonstrated by means of two examples.

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 ...

Experimental and Theoretical Investigation of Acoustic Metamaterial with Negative Bulk-Modulus

N. R. Mahesh, and P. Nair
SSN College of Engineering
Tamil Nadu, India

Acoustic metamaterials are structured materials of negative mass density or negative bulk-modulus or both of them. Materials are tailored in sub-wavelength dimensions so as to get these negative properties. This paper compares the result of an experimental investigation of acoustic metamaterial with negative bulk-modulus to its COMSOL modeling. The resonance characteristics of single ...