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.

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 ...

Design of Traveling Wave Ultrasonic Vibration Disk for Nano-particles in Liquid Dispersion

J. Muraoka, and T. Suzuki
Yamagata Research Institute of Technology

The traveling wave ultrasonic vibration disks for dispersion of particles were designed by using of FEM analysis. The vibration disks are required specific vibration pattern, which contains three nodal lines. The vibration disk thickness was calculated to be matched the resonance frequency of bolted langevin type transducer and the specific vibration pattern. The alignment of the transducer was ...

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 ...

Optimization of an Acoustic Waveguide for Professional Audio Applications

M. Cobianchi[1] and R. Magalotti[1]
[1] B&C Speakers S.p.a., Bagno a Ripoli, FI, Italia

In modern live sound reinforcement there is a growing use of line sources, obtained through the stacking of many loudspeakers with properly controlled wavefront shape. Thus the use of waveguides is mandatory in order to modify the shape and size of the wavefront exiting from professional compression drivers. With the help of COMSOL Multiphysics®, we have designed a waveguide featuring an ...

Optimal Placement of Piezoelectric Plates to Control Multimode Vibrations of Rotating Beam

F. Botta[1], D. Dini[2], S. Gentili[1], G. Cerri[1]
[1]Dipartimento di Ingegneria Meccanica e Industriale, UniversitĂ  degli Studi di Roma Tre, Roma, Italy
[2]Department of Mechanical Engineering, Imperial College London, London, United Kingdom

Turbomachines blades are forced by a load resulting from the interaction with the fluid. The consequent vibrations, and the associated fatigue phenomena, can give catastrophic failures and the reduction of the blades life. It could be increased if damping system are used. The piezoelectric materials has received considerable attention by many researcher for their potential application in the ...

Flow Focusing Droplet Generation Using Linear Vibration - new

A. Salari[1], C. Dalton[1]
[1]Department of Electrical & Computer Engineering, University of Calgary, Calgary, AB, Canada

Flow focusing microchannels are widely used in droplet generation mechanisms. In this paper, the effect of linear vibration on the flow pattern in a flow focusing structure and the corresponding formed droplets were numerically investigated using COMSOL Multiphysics® software. The results showed that vibration can be very effective on droplet formation, if the governing parameters such as ...

On the Numerical Modeling of Elastic Resonant Acoustic Scatterers

V. Romero-García[1], A. Krynkin[2], J.V. Sánchez-Pérez[1], S. Castiñeira-Ibáñez[3], and L.M. Garcia-Raffi[4]
[1]Centro de Tecnologías Físicas Acústica, Universidad Politécnica de Valencia, Valencia, Spain
[2]School of Computing, Science & Engineering, University of Salford, Salford, United Kingdom
[3]Depto. Física Aplicada, Universidad Politécnica de Valencia, Valencia, Spain
[4]Instituto Universitario de Matemática Pura y Aplicada, Universidad Politécnica de Valencia, Valencia, Spain

The elastic and geometrical properties of Low Density Polyethylene (LDPE) foam are used in this paper to improve the attenuation properties of periodic arrangements of acoustic scatterers known as Sonic Crystals (SCs). A specific recycled profile of LDPE foam is used as elastic-acoustic scatterer. The acoustic spectrum of the single scatterer shows two attenuation peaks in the low frequency ...

Computational Modeling of Wave Propagation in a Geophysical Domain

J. McKenna[1], M. McKenna[1], S. Yushanov[2], J. Crompton[2], and K. Koppenhoefer[2]
[1]U.S. Army Engineering Research and Development Center
[2]ACES of Columbus, LLC, Columbus, OH, USA

The propagation of shear (S) and compression (P) waves within the earth allows geologists to track seismic events and to identify subterranean structure. This work shows the strong effect of including the variation of wave speed through the top thirty meters of the earth. By including this variation in material properties, the wave arrival time and frequency content agree with experimental data. ...

Innovating New Products using Multiphysics Modeling

Dr. Shekhawat is currently the General Manager for New Products Development at Secure Meters Ltd., Udaipur. Prior to this, he was with CEERI, Pilani for 23 years. He has a Ph.D., MS, M. Sc. (Physics) and BE (EEE) from BITS, Pilani. He is the recipient of several honours including the DAAD Fellowship, Germany and National Science Talent Fellowship. His areas of research include Ultrasonic ...

Characterization of a Tonpilz Transducer and Performance Analysis for a MEMS-Transducer Array

V. Vadde, and B. Lakshmi G

In this paper, we develop and analyze a standard piezoacoustic Tonpilz-transducer model for underwater acoustics in Comsol by addressing the attendant piezoelectric and pressure acoustic multiphysics phenomena. Transducer properties that are studied and characterized are the center frequency, bandwidth, linearity, sensitivity, and noise figure. In an effort to miniaturize the transducer, a ...