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.

Accuracy of Fully Coupled Loudspeaker Simulation Using COMSOL

M. Hedges[1][2] and Y.W. Lam[1]
[1]Acoustics Research Centre, School of Computing, Science & Engineering, University of Salford, Salford, United Kingdom
[2]Monitor Audio Ltd., Rayleigh, Essex, United Kingdom

Loudspeaker simulation is used to inform the designer as to the performance of a design. In recent years the Finite Element Method (FEM) has been used to model the mechanical and acoustical attributes of a loudspeaker with varying success. This paper shows how a model that incorporates the magnetic, electromagnetic, mechanical and acoustical domains performs. These domains will be coupled where ...

The Acoustoelastic Effect: EMAT Excitation and Reception of Lamb Waves in Pre-Stressed Metal Sheets

R.M.G. Ferrari[1]
[1]Danieli Automation S.p.A., Buttrio, UD, Italy

The acoustoelastic effect relates the change in the speed of an acoustic wave travelling in a solid, to the pre-stress of the propagation medium. In this work the possibility of assessing nondestructively the stress status in metal sheets, by using the acoustoelastic effect, is investigated. As the effect turns out to be very small for practical values of applied stress, the proposed technique ...

A Multiphysics Approach to the Design of Loudspeaker Drivers

R. Magalotti [1]
[1] B&C Speakers, Bagno a Ripoli, Italy

Loudspeaker drivers are energy transducers: their main goal is to efficiently convert electrical energy to acoustic energy (sound), through the movement of mechanical parts. As such, they are prime candidates for the application of multiphysics methods and tools. The talk will outline the growing set of tools that COMSOL Multiphysics® software puts in the hands of the loudspeaker designer; ...

An Improved Loudspeaker Frequency Response by Using a Structure of Rigid Absorptive Panel in a Vented Cabinet - new

R. Balistreri[1]
[1]Community Light & Sound Inc., Chester, PA, USA

When placing a loudspeaker in a cabinet, standing waves inside the cabinet affect the frequency response with ripples. This peaks and dips due to pressure cancellation inside the cabinet have an effect on the diaphragm and generating sound out from the vents. If it was in a condition of total absorption of the sound waves at the back of the diaphragm, the transducer would otherwise have a much ...

Modeling and Simulation of MR Dampers Using COMSOL Multiphysics® Software

Y. M. Khedkar[1], S. B. Joshi[2], P. M. Pawar[1], B. P. Ronge[1]
[1]SVERI's College of Engineering, Pandharpur, Maharashtra, India
[2]Brahmdevdada Mane Polytechnic, Solapur, Maharashtra, India

Classical hydraulic dampers are flexible devices that are used to attach a component to a mounting base. Vibration amplitude reduction can be achieved by improving the old technique of suspension by bringing in application of Magnetorheological or Electrorheological fluid in it. Due to the controllable characteristics of the material used in the classical hydraulic damper, the design and ...

CMUT Based Free Membrane Intra-Cardiac Volumetric Blood Flow-Meter

P. Priya [1], B. D. Pant [2],
[1] Birla Institute of Technology and Science Pilani, Pilani, Rajasthan, India
[2] CSIR-Central Electronics Engineering Research Institute, Pilani, Rajasthan, India

In this paper, a free membrane is used as a receiver to increase the capacitance and therefore the resolution of the flow meter. For the current application, from the wavelength of sound wave in soft tissue (c= 1540 m/s) the resolution was calculated to be 0.48 mm. This gives the first Eigen frequency of the capacitive structure according to which the poly silicon membrane was designed. After ...

Acoustic Field Comparison of High Intensity Focused Ultrasound Using Experimental Characterization and Finite Element Simulation

J. L. Teja[1], A. Vera[1], L. Leija[1]
[1]Department of Electrical Engineering, Cinvestav-IPN, Mexico D.F., Mexico

High Intensity Focused Ultrasound (HIFU) is used as a noninvasive technique of tissue heating and ablation for different medical treatments. This paper presents a quantitative comparison of HIFU acoustic fields experimentally obtained versus simulated acoustic fields. Acoustic field characterization was realized in two HIFU transducers using water as a propagation medium. Also, simulations were ...

Simulation of a Piezoelectric Loudspeaker for Hearing Aids and Experimental Validation - new

G. C. Martins[1], P. R. Nunes[1], J. A. Cordioli[1]
[1]Federal University of Santa Catarina, Florianópolis, SC, Brazil

The use of piezoelectric materials in hearing aid loudspeakers, also called receivers, presents technical and economic advantages such as reducing the number of parts of the system and its manufacturing cost. However, the performance of such systems is still not competitive when compared to traditional electrodynamic loudspeakers. In order to achieve an appropriate performance, one option is to ...

Solid Rocket Motor Combustion Instability Modeling in COMSOL Multiphysics® Software

S. R. Fischbach [1][2],
[1] Jacobs ESSSA Group, NASA Marshall Space Flight Center, Huntsville, AL, USA
[2] Qualis Corporation, Huntsville, AL, USA

Combustion instability modeling of Solid Rocket Motors (SRM) remains a topic of active research. Many rockets display violent fluctuations in pressure, velocity, and temperature originating from the complex interactions between the combustion process, acoustics, and steady-state gas dynamics. Recent advances in defining the energy transport of disturbances within steady flow-fields have been ...

3D Acoustic Streaming Field in High-Intensity Discharge Lamps - new

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

High-intensity discharge lamps will in the foreseeable future be important light sources despite a growing market share of LEDs. Cost and energy efficient high frequency (300 kHz) operation is hampered by the excitation of acoustic resonances inside the arc tube, which results in low frequency (10 Hz) light flicker. Our aim is to calculate the acoustic streaming velocity field, which is related ...