N. Krishnan, H. Nemade[1,2], and R. Paily
Centre for Nanotechnology, Indian Institute of Technology Guwahati, Assam, India
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 ...
Alcon Research Ltd., Lake Forest, CA, USA
Anomalous acoustic streaming is observed from sharp edges of vibrating solid bodies in fluids. The streaming velocities can be orders of magnitude higher than expected from the Rayleigh streaming at similar amplitudes of vibrations. Acoustic velocity of a fluid relative to a solid body diverges at a sharp edge giving rise to a localized time-independent body force acting on the fluid. The ...
A-S.Moreau, H.Lissek, and F. Bongard
Ecole Polytechnique Fédérale de Lausanne, Switzerland
JAST SA, Antenna Systems, Lausanne, Switzerland
In this context, a one-dimensional acoustic transmission line, exhibiting metamaterial properties, is presented. It is composed of an acoustic waveguide, periodically loaded with membranes having the function of series capacitances, as well as transversally connected open channels (denoted stubs) having the function of shunt inductances. A validation of the transmission line design is made ...
Application of a Weakly Non-Linear Analysis to the Analysis of Thermoacoustic Combustion Instabilities - new
D. Laera, S. M. Camporeale, G. Campa
Politecnico di Bari, Bari, Italy
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”) ...
N. Chowdhury, Z. Liao, and L. Zhao
Department of Electrical & Computer Engineering, Ryerson University, Toronto, ON, Canada
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 ...
S. H. Abadi , A. T. Lim ,
 University of Washington, Bothell, WA, USA
Underwater acoustics is an area that studies the sound propagation in water and the interactions with other objects and water boundaries. There are many technologies available for acoustic exploration of the ocean. Underwater vehicles are robots used in ocean sciences that travel underwater autonomously and can tow a hydrophone as a mobile sensor to record sound. The turbulent flow induced by ...
Qingwei Liu , Hangjie Mo 
 Shanghai Jiao Tong University, Shanghai, China
This paper studies the application of laminate magnetoelectric (ME) material in displacement sensor. We studied the L-L block composite thanks to designed structure by coupling displacement signal with the displacement potential of ME composite. A nonlinear approximation is adapted to modeling magnetostrictive phase and implemented in COMSOL Multiphysics® software. The simulation results ...
Guided Wave in Engineering Structures Using Non-Contact Electromagnetic Acoustic Transducers: A Numerical Approach for the Technique Optimisation
S. Soua, A. Raude, and T-H. Gan
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 ...
R.Christensen, and U. Skov
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 ...
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 ...