Aqui você encontrará apresentações realizadas nas Conferências de Usuários COMSOL de todo o mundo. As apresentações englobam pesquisas e produtos inovadores feitas por engenheiros e cientistas usando o COMSOL Multiphysics. Os tópicos abrangem uma grande gama de indústrias e aplicações, como elétrica, mecânica, escoamento e química. Use a função de busca "Quick Search" para encontrar apresentações na sua área de interesse.

Compression Driver Simulation Including Air Damping in Phase Plug

R.Christensen, and U. Skov
iCapture ApS
Gadstrup, Denmark

A compression driver is a certain type of electrodynamic loudspeaker which has a phase plug with slits in front of the diaphragm. The slits are narrow enough that the so-called viscothermal effects are of significant importance. In this paper a 2D axisymmetric finite element model of a commercial compression driver is established where the vibroacoustic behavior can be evaluated. The ...

PCCP Profiling and Tube Wave Analysis of WRE Signal

N. Chowdhury[1], Z. Liao[2], and L. Zhao[1]
[1]Department of Electrical & Computer Engineering, Ryerson University, Toronto, ON, Canada
[2]Department of Architectural Science, Ryerson University, Toronto, ON, Canada

Acoustic wave propagation due to the breakage or slippage of reinforced wire in water-filled prestressed concrete cylinder pipe (PCCP) attracts interest in non-destructive pipe testing. Current practice of acoustic emission (AE) detection and wire-break related events (WRE) recognition is based on field data analysis. This work deals with the theoretical investigation of WRE signal from ...

Application of a Weakly Non-Linear Analysis to the Analysis of Thermoacoustic Combustion Instabilities - new

D. Laera[1], S. M. Camporeale[1], G. Campa[2]
[1]Politecnico di Bari, Bari, Italy
[2]Ansaldo Energia, Genoa, Italy

The thermoacoustic combustion instabilities are complex phenomena that may occur in steady flow combustion systems that are aboard of, e.g., rocket engines or gas turbines. The phenomena involve the interaction of chemical reactions with fluid-dynamic and propagation of pressure waves in the combustion chamber. Combustion instabilities may lead to a stable condition (known as “limit-cycle”) ...

Design and Implementation of Multichannel Piezoelectric Acoustic Sensor

R. S. Hallikar [1], S. Munshi [1], M. U. Kumari[1], K. Padmaraju[2],
[1] R. V. College of Engineering, Bengaluru, Karnataka, India
[2] JNTU Kakinada, Kakinada, Andhra Pradesh, India

This paper concentrates on developing a self-contained cochlea whose performance is at par with natural hearing. The Artificial Basilar Membrane (ABM) design is done in such a manner so as to get a performance similar to the natural hearing. Finite element analysis was done with the help of COMSOL Multiphysics software. Two materials, Polyvinylidene fluoride (PVDF) and lead zirconate titanate ( ...

Quartz Transducer Modeling for Development of BAW Resonators

L.B.M. Silva[1], E.J.P. Santos[1]
[1]Laboratory for Devices and Nanostructures, Electronics and Systems Department, Universidade Federal de Pernambuco, Recife, PE, Brasil

Transducer optimization is a key aspect for successful development and deployment of advanced sensors, especially when designing 3D structures for harsh environments. For piezoelectric transducers, plate thickness determines the operating frequency of the resonator, which is frequently tuned in the shear thickness vibration mode. Quartz has been the material of choice for the fabrication of ...

Simplified Finite Element Simulation of a SAW Hydrogen Sensor using COMSOL Multiphysics

N. Krishnan[1], H. Nemade[1,2], and R. Paily[2]
[1]Centre for Nanotechnology, Indian Institute of Technology Guwahati, Assam, India
[2]Department of Electronics and Communication Engineering, Indian Institute of Technology, Assam, India

In this paper, we discuss a simplified finite element method simulation of surface acoustic wave (SAW) delay line hydrogen sensor using COMSOL Multiphysics.  A delay line SAW sensor consists of a transmitting interdigital transducer (IDT) and a receiving IDT separated by a few wavelengths. In this work, the number of degrees of freedom to solve for the SAW delay line sensor model ...

Orientation of Piezoelectric Crystals and Acoustic Wave Propagation

G. Zhang[1]
[1]Clemson University, Clemson, SC, USA

Surface acoustic wave (SAW) devices are commonly used as wireless filters, resonators, and sensors. The confinement of acoustic energy near the surface of a piezoelectric substrate in a SAW sensor makes it highly sensitive for discerning surface perturbation. As sensors, SAW devices have the potential to provide a high-performance sensing platform with capabilities of remote and high-temperature ...

A Finite Element Model of Shear Wave Propagation Induced by an Acoustic Radiation Force Impulse

R. De Luca[1,2], J. Fromageau[1], H.W. Chan[1], F. Marinozzi[2], J. Bamber[1]
[1]Institute of Cancer Research and Royal Marsden Hospital, Sutton, England, United Kingdom
[2]Sapienza University of Rome, Dept. of Mechanical and Aerospace Engineering, Rome, Italy

Shear wave elastography is an innovative technique used in combination with the traditional ultrasound imaging to improve the specificity of cancer imaging. A two-dimensional finite element model (FEM), composed of realistic boundary conditions, was developed in COMSOL Multiphysics® to simulate the propagation of shear waves induced by an acoustic radiation force impulse (ARFI) in isotropic, ...

Guided Wave in Engineering Structures Using Non-Contact Electromagnetic Acoustic Transducers: A Numerical Approach for the Technique Optimisation

S. Soua[1], A. Raude[1], and T-H. Gan[1]
[1]NDT Technology Group, TWI Ltd, Cambridge, United Kingdom

There are over 10 million kilometers of pipes and pipelines around the world that carry hazardous fluids and gases. Fluids include oil, oil products, chemicals such as solvents, caustics, acids, corrosives and combustibles often at high pressure and temperature. These pipes are susceptible to corrosion if they are not protected properly by the environment or the contents. Inspection of pipes is ...

Design and Simulation of an Orbiting Piezoelectric MEMS Gyroscope Based on Detection of Phase-Shift Signals - new

S. Gorelick[1], J. R. Dekker[1], B. Guo[1], H. Rimminen[1]
[1] VTT Technical Research Centre of Finland, Espoo, Finland

The feasibility of phase-sensitive detection of angular-rates using bi-directional orbiting piezoresonators suspended by thick annular springs with thin-film aluminium nitride piezoactuators on top of them was investigated. The ring-shaped flexures are more suitable for supporting the orbiting motion due to their angle-dependent spring constant. The response of the orbiting resonators to ...