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.

Optimal Design of Slit Resonators for Acoustic Normal Mode Control in Rectangular Rooms

S. Floody[1], R. Venegas[2], and F. Leighton[3]
[1]Universidad de Chile, Facultad de Artes, Departamento de Música y Sonología, Licenciatura en Sonido, Santiago, Chile
[2]University of Salford, Acoustics Research Centre, Salford, UK
[3]Universidad Tecnológica de Chile Inacap, Sede Pérez Rosales, Santiago, Chile

The present article presents a method to redistribute the acoustic modes of a rectangular enclosure in the low frequency range using slit resonators. The objective of the present work is to compare different strategies of optimal design in order to determine the dimensions of the resonators. The method of the finite elements will be used to model the acoustic physical behavior of the room. In ...

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”) ...

Finite Element Analysis into Eigenfrequencies of a Total Hip Stem with Different Levels of Loosening

T. Bender [1], M. Sass [1], W. Mittelmeier [1], R. Bader [1], D. Kluess [1]
[1] Department of Orthopaedics Research Laboratory for Biomechanics & Implant Technology, University Medicine Rostock, Rostock, Germany

A finite element model of a total hip replacement (THR) has been developed from the approach of modal analysis. The model is capable of determining the first 15 Eigenmodes of a THR with an artificial bone model. The model was equipped with several different defects to simulate a loosening of THR and to enforce a shifting of the frequency spectrum of the system’s Eigenfrequencies. Using the ...

Underwater Flow Noise Simulation

S. H. Abadi [1], A. T. Lim [1],
[1] 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 ...

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 ...

Optimization of an Acoustic Waveguide for Professional Audio Applications

M. Cobianchi[1] and R. Magalotti[1]
[1] B&C Speakers S.p.a., Bagno a Ripoli, FI, Italia

In modern live sound reinforcement there is a growing use of line sources, obtained through the stacking of many loudspeakers with properly controlled wavefront shape. Thus the use of waveguides is mandatory in order to modify the shape and size of the wavefront exiting from professional compression drivers. With the help of COMSOL Multiphysics®, we have designed a waveguide featuring an ...

Investigation of Mean-Flow Effects on Tubular Combustion Chamber Thermoacoustics Using a Burner Transfer Matrix Approach - new

A. Andreini[1], B. Facchini[1], A. Innocenti[1], D. Pampaloni[1]
[1]University of Florence, Florence, Italy

The paper presents a methodology to account for local mean-flow effects on thermo-acoustic instabilities to improve typical calculations performed under the zero-Mach number assumption. A 3D FEM model of a simplified combustor is solved with COMSOL Multiphysics® Pressure Acoustics interface. The Helmholtz equation is used to model the combustor and the classical k-τ model for the Flame Transfer ...

A Virtual Product Development Environment for Electronic Hydraulic Power Steering Pump via Multiphysics Modeling

F. Qi [1], J. Men [1], L. Yang [1], Z. Bing [1] , J. Yang [1], F. He [2], L. Pan [2], Z. Shao [2], G. Gao [2], X. Zhang [3], H. Wei [3], S. Duo [3], L. Song [3], X. Wang [3], Z. Wang [3], G. Wei [3], Y. Li [3], H. Yang [3], Z. Ma [3], B. Li [3], Y. Zhang [3], Y. Li [3], Y. Xie [3], D. Yu [3]
[1] FZB Technology, Inc., Plymouth, MI, USA
[2] Shenzhen South Dare Auto Parts, Ltd., Shenzhen, China
[3] Fuxin Dare Auto Parts, Ltd., Fuxin, China

Using advanced computational fluid dynamics software PumpLinx and the COMSOL Multiphysics® software, a virtual product development environment was established for the electro-hydraulic power steering pump system in a passenger vehicle. The model built with the COMSOL Multiphysics® software provides a complete design optimization and validation framework. The success of the framework depends on ...

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 ...

Acoustic Streaming of a Sharp Edge

M. Ovchinnikov[1]
[1]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 ...