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.

Linear Water Wave Propagation around Structures

L. Martinelli, and A. Lamberti
Universita di Bologna, Italy

Objective of this contribution is to show how to implement the Mild Slope Equations with COMSOL Multiphysics. These equations are commonly used to study the propagation of waves in harbors. Some interesting features are presented, namely the use of weak terms (used for the modelling of the source term); the evaluation of a smooth phase gradient from the complex dependent variable; a robust ...

Virtual Acoustic Prototyping – Practical Applications for Loudspeaker Development

A. Salvatti
JBL Professional, Northridge, CA, USA

The author presents an overview of methods to build virtual prototypes of both horns and loudspeaker drivers which allows a significant reduction in the number of physical prototypes, as well as reduced development time. This paper will present some of the practical results from work the author has performed in the course of designing both transducers and horns using COMSOL Evolution of the ...

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

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

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 ...

Comparison of an Analytical and Numerical Solution for the Landmine Detection Problem

M. Mattingly[1], K. McIlhany[2], and R. Malek-Madani[3]

[1]Applied Research Laboratory, The Pennsylvania State University, University Park, PA, USA
[2]Physics Department, United States Naval Academy, Annapolis, MD, USA
[3]Mathematics Department, United States Naval Academy, Annapolis, MD, USA

Acoustic landmine detection is accomplished using a loud speaker as an airborne source to generate low-frequency waves that enter the soil at a certain incident angle. At a specific frequency, the landmine will "vibrate" at resonance, imparting a certain velocity on the soil particles above it that is detected by a scanning Laser Doppler Vibrometer system. The ability to mathematically predict ...

Design of Resonator for Ultrasonic Motor with Vibrational Transmission Line using COMSOL

H. Tamura
Tohoku Institute of Technology
Japan

This paper is in Japanese.

Modeling and Experimental Verification of the Power Transfer and Thermal Characteristics of Piezoelectric Transformers Subjected to Combined Mechanical and Electrical Loading

S. Tuncdemir[1], W.M. Bradley[2]
[1]Solid State Ceramics, Williamsport, PA, USA
[2]QorTek, Williamsport, PA, USA

A piezoelectric transformer allows purely mechanical transfer and scaling of electrical energy via simultaneous utilization of both the direct and converse piezoelectric effects. This mechanical energy transfer enables a wide range of functional differences from typical magnetic-based electrical power transformers. Comparing to their electromagnetic counterparts, piezoelectric transformers are ...

Simulation of Helmholtz Resonators for Optical Gas Sensing: Comparison Between Pressure Acoustics and Thermoacoustics - new

B. Parvitte[1], C. Risser[1], R. Vallon[1], V. Zéninari[1]
[1]Université de Reims, Reims, France

Among optical gas sensing methods, photoacoustic (PA) spectroscopy combined with a laser source has proven to be a very robust and sensitive method for trace gas detection. COMSOL Multiphysics® software was used to calculate the frequency response of differential Helmholtz resonator cells in order to optimize the detection limit of PA sensors. Two different kind of simulation were performed: ...

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 ...

Application of COMSOL to Acoustic Imaging

K. Mcilhany, and J.C Hernandez
U.S. Naval Academy, Annapolis, MD, USA

Acoustic Imaging of hand movement is being studied with COMSOL and Matlab. A hardware implementation is being pursued that will be an array of 16x16 ultra-sonic speakers placed in a grid facing a similar grid of 16x16 microphones, operating at 40kHz. COMSOL is used to repeatedly calculate the diffraction pattern from a small scattering center, approximately 1.0cm in diameter. In conjunction ...

A Lesson in Cartilage Therapy: Do Chondrocytes Utilize Mechanical Energy from Exercise for Cell Maintenance and Growth?

A. Miller [1], H. Viljoen [1], A. Chama [2], T. Louw [2],
[1] Department of Chemical and Biomolecular Engineering, University of Nebraska - Lincoln, Lincoln, NE, USA
[2] Department of Chemical Engineering, Stellenbosch University, Stellenbosch, South Africa

- Using COMSOL Multiphysics® Acoustics Module: Chondrocytes modeled attached to a plane (to mimic in vivo constraints) are shown to resonate near 5MHz. At resonance, the mechanical energy density in the nucleus is two times higher than in the cytoplasm. - Impact exercise is modeled as traveling pressure pulses and shown to cause cells to vibrate primarily at the resonance frequency. - Two ...