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.
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Time-Domain Model of the Inner Ear to Study Nonlinear Responses

K. Gladine [1], J. Soons [1], J. Dirckx [1]
[1] University of Antwerp, Belgium

The ear doesn’t solely listen but it also speaks. Sounds formed in the inner ear which are measurable in the outer ear are called Otoacoustic emissions (OAEs). Some claim these are produced by the outer hair cells (OHCs), the amplifiers in the inner ear. Our hypothesis is that the OHCs only amplify distortion products (DPs) but do not produce them.

Simulating the Response of Planar Photonic Structures Under the Strain of Surface Acoustic Waves

O. D. D. Couto Jr. [1], A. C. T. Covacevice [1],
[1] Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Campinas, SP, Brazil

In this contribution, we simulate the optical response of piezoelectric planar optical microcavities (POMCs) under the modulation introduced by a propagating surface acoustic wave (SAW). The physical picture of the model is shown in Figure 1. A metallic interdigital transducer (IDT) is placed on the sample surface and, via inverse piezoelectric effect, is responsible for the generation of SAWs ...

Vibro-Acoustic Analysis of Motorcycle Engine Under Combustion Load - new

U. Mohite[1], N. Bhatia[1]
[1]Mahindra Two Wheelers Ltd., Pune, Maharashtra, India

Noise radiated from automotive engine is gaining significance in order to meet regulations concerning noise levels and to fulfill customer demands of quiet products. In IC engines, combustion pressure is one of the major excitations which is transmitted through powertrain to the casings and radiates noise. Structural and acoustical modeling and simulation methods can be used to predict and ...

CFD Analysis of a Macroscale Ultrasonic Separator

K. Chitale [1], B. Lipkens [1, 2], W. Presz, Jr. [1],
[1] FloDesign Sonics Inc., Wilbraham, MA, USA
[2] Western New England University, Springfield, MA, USA

Macroscale ultrasonic separation is a new filtration technology, with various applications such as cell clarification, cell therapy, blood-lipid separation, oil-water separation etc. These systems use piezoelectric transducers to create standing waves in fluid-particle mixture. Suspended particles get clustered by action of acoustic radiation forces and are separated out by enhanced gravity ...

Application of Transfer Matrix Method in Acoustics

G. Campa, and S.M. Camporeale
Politecnico di Bari, Bari, Italy

The Transfer Matrix method in the Acoustics Module of COMSOL Multiphysics is used when the whole system can be represented into a sequence of subsystems that interact only with adjacent subsystems. This method is frequently used in mathematics and, particularly, in acoustics. The application of the present method is really useful, because it permits to break the total system into a network of ...

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 ...

Modeling the response of photoacoustic gas sensors

S.L. Firebaugh[1], F. Roignant[2], and E.A. Terray[3]

[1]United States Naval Academy, Annapolis, Maryland, USA
[2]Polytechnique Nantes, Nantes, France
[3]Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA

A fast, high-sensitivity detector is required for studies of environmentally relevant gases. Photoacoustic spectroscopy (PAS), an absorption spectroscopy technique in which absorption is detected as sound, is explored as a possible solution. A tuning-fork based PAS sensor is modeled using COMSOL. The model combines the acoustic and piezoelectric modules and also includes viscous damping. The ...

Designing a Smart Skin with Fractal Geometry

S. Ni, C. Yang Koh, S. Kooi, and E. Thomas
Institute for Soldier Nanotechnologies
Dept. of Materials Science and Eng.
MIT
Cambridge, MA

Recently, the concepts of fractal geometry have been introduced into electromagnetic and plasmonic metamaterials. With their self-similarity, structures based on fractal geometry should exhibit multi-band character with high Q factors due to the scaling law. However, there exist few studies of phononic metamaterials having fractal geometry. COMSOL is used to investigate vector elastic and ...

Simulation of Pearl-Chain Formation of Microparticles by Acoustic Standing Waves, including Inter-Particle Forces and Collisions

T. Baasch [1], J. Dual [1],
[1] ETH Zurich, Insitute for Mechanical Systems, Zurich, Switzerland

Acoustic standing waves can be used to manipulate micrometer sized particles, cells and organisms. In most applications these objects are driven towards pressure nodal lines, predominantly by the primary acoustic radiation force. Interestingly, at intermediate particle concentrations, detailed phenomena of line-formation and inter-line repulsion occur. Such phenomena are believed to be caused by ...

Analysis of High-Frequency Thermoacoustic Instabilities in Lean, Premixed Gas Turbine Combustors

F. Berger [1], T. Hummel [1], P. Romero [1], M. Schulze [1], B. Schuermans [2], T. Sattelmayer [1],
[1] Lehrstuhl für Thermodynamik, TU München, Germany
[2] GE Power, Switzerland

Modern gas turbine systems for power generation are prone develop so-called thermosacoustic instabilities in the combustion chamber. Physically, these instabilities emerge as large amplitude pressure oscillations within the combustor, which are caused by constructive feedback interactions between the flame and the combustor's natural acoustic modes. The oscillations disturb the combustion ...