H. Bruus, P.B. Muller, R. Barnkob, M.J.H. Jensen
Technical University of Denmark, Kongens Lyngby, Denmark
COMSOL, Kongens Lyngby, Denmark
We have simulated the ultrasound-induced acoustophoretic motion of microparticles suspended in an aqueous solution. The full first-order thermoviscous acoustics equations have been implented on a rectangular microfluidic 2D domain excited with an ultrasound field tuned to resonance near 2 MHz. The micrometer-thin but crucial viscous boundary layers at the rigid walls have been fully resolved. The ...
T. Graf, T. Gisler, P. Sollberger, O. Schaelli
School of Engineering and Architecture, Lucerne University, Horw, Switzerland
Axisymmetric acoustic waves propagating along buried water pipes have been investigated by FEM and experimentally. Universal dispersion relations of the fundamental mode were obtained as a function of the standard dimension ratio SDR and of the material surrounding the pipe (soil, air). At low frequency there exists little dispersion and the “dc” phase velocity of the leak noise is ...
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 ...
Dinex Emission Technology A/S, Middelfart, Denmark
Exhaust noise must meet legislation targets, customer expectations and cost reduction which call for design optimization of the exhaust systems in the design phase. One solution is to use 3 dimensional linear pressure acoustics and calculate the transfer matrix of the muffler. The transfer matrix is the basis for calculating either the insertion loss or transmission loss of a muffler. The 3D ...
Teledyne Technologies Inc., Falmouth, MA, USA
This paper describes the COMSOL Multiphysics® simulation and the test of a low-frequency (500Hz) sound source for long-range acoustic communications. This design uses innovative carbon-fiber composite materials.To meet the demand for the frequency range the doubly resonant organ pipe resonator was suggested. A multi-resonant system usually needs a precise, complicated adjustment of its ...
Scale-up Design of Ultrasound Irradiator for Advanced Oxidation Process (AOP) Using COMSOL Multiphysics® Simulation
The Ohio State University, Columbus, OH, USA
Ultrasound is a promising green technology for the advanced oxidation process (AOP) since it adds no chemicals to the treated water. In this paper, COMSOL Multiphysics® was used as a tool to design and characterize an ultrasound irradiator with multi-stepped configuration, which aims to overcome disadvantages of typical irradiators and to enhance contaminant removal in large-scale water ...
R. Haettel, A. Daneryd, M. Kavasoglu, C. Ploetner
ABB Corporate Research, Västerås, Sweden
ABB Transformers, Varennes, QC, Canada
Today, low noise is a mandatory feature for power transformers to comply with customer specifications and environmental regulations. Therefore, it is crucial to develop sound prediction tools with sufficient accuracy to avoid overkill margins in design and costly modifications after transformer completion. The paper will focus on core noise which is a typical multiphysics phenomenon involving ...
Rakesh Kumar Pati , SK Mohammed ali, Sakuntala Mahapatra, Millee Panigrahi
MEMS Design Centre, Dept. of ETC, Trident Academy of Technology, Bhubaneswar, Odisha, India
Despite of the existing successful clinical applications, however, the interaction, i.e. artificial sensing, between the robot and the patient is still very limited. With the help of various cameras, vision is almost the only feeling that a robot can have. In order to imitate the human skin, various signals e.g., the strength of pressure, change of strength, speed and acceleration should be ...
Modeling of Ultrasonic Transducers and Ultrasonic Wave Propagation for Commercial Applications Using Finite Elements with Experimental Visualization of Waves for Validation - new
D. R. Andrews
Cambridge Ultrasonics, Over, UK
Finite element (FE) modelling of ultrasonic propagation using COMSOL Multiphysics® simulations can be used to create images of waves. Unfortunately, in time-stepping solutions, it is possible for numerical instabilities to grow large and dominate the solution adversely. Any design of transducer that is based upon poorly-configured FE models is unlikely to perform as expected and will almost ...
B. Goldsberry, M. Isakson
Applied Research Laboratories, The University of Texas at Austin, Austin, TX, USA
Measuring geoacoustic parameters of underwater sediments is important for accurate modeling of underwater acoustic propagation. While the density and compressional wave speeds can be directly measured in sediments, shear wave speeds are difficult to measure because they are highly attenuated. However, shear wave speeds can be indirectly determined through measurement of Scholte interface wave ...