K. McIlhany, and R. Malek-Madani
Physics Department, United States Naval Academy, Annapolis, MD, USA
Mathematics Department, United States Naval Academy, Annapolis, MD, USA
In 1966, mathematician Mark Kac proposed the question "Can One Hear the Shape of a Drum?" in an article for American Mathematical Monthly. In attempting to resolve the Chesapeake Bay from an eigenfunctional approach, a one-to-one mapping of this famous problem has been identified. The quote above will re-write to "Can One Hear the Shape of a Drum from Multiple Point-Sampled Spectra?". This ...
F. Teuma Tsafack, K. Kochan, T. Kletschkowski, and D. Sachau
Helmut Schmidt University/ University of the Federal Armed Forces Hamburg, Germany
This paper presents an important step in developing a combined active noise- and audio system for a light jet. To prepare its installation both a wooden mock-up and a finite element model of the investigated cavity were created. Sensitivity analysis and key parameters selection were done in order to validate the model. Error analysis between measured and computed data closes the ...
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 ...
M. Zampolli, N. Malm, and A. Tesei
NURC NATO Research Centre, La Spezia, Italy
COMSOL AB, Stockholm, Sweden
Perfectly matched layers (PML) are an efficient alternative for emulating the Sommerfeld radiation condition in the numerical solution of wave radiation and scattering problems. The key ingredient of the PML formulation is the complex scaling function, which controls the anisotropic damping of the PML. The objective of this study is to propose a modified complex scaling function capable of ...
P.R. Basha, B. Mishra, and A. Zachariah
School of Electronics Engineering, VIT University, Vellore, Tamil Nadu, India
The realization of miniature SAW device is compatible on CMOS device for mobile and wireless communication system has become very important in recent years. Acoustic wave propagation along the surface of a piezoelectric material provides a means of implementing a variety of signal processing devices at frequency ranging from several MHz to a few GHz. In this work, a Miniature SAW device is ...
S.L. Firebaugh, E.A. Leckie, J.A. Piepmeier, and J.A. Burkhardt
United States Naval Academy, Annapolis, Maryland, USA
Microrobotics has promising applications in microsurgery and microassembly. A challenge in these systems is interfacing with the robot. This project explores crawling robots that are powered and controlled through a global mechanical vibration field. By controlling the frequencies present in the vibration field, the user can then steer the robot. The “robot” has a rectangular body with ...
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 ...
Beam Structure As an Acoustic Wave Sensor: A Study of the Effect of Sensor Design on Its Sensitivity to Noise
F. Akasheh, A. Biddle, W.S. Shepard Jr., and B.B.B. Zhang
Tuskegee University, Tuskegee, AL, USA
University of Alabama, Tuscaloosa, AL, USA
The detection and identification of the location of a sound source is commonly done using arrays of microphones. A recent new alternative approach has been proposed which involves the use of continuous structures, such as beams or plates, as acoustic wave sensors. The sound wave impinging on the surface of the structure causes it to vibrate and the measured surface displacements can then be used ...
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 ...
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 with ...