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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Simulating Acoustic Combustion Chamber Eigenmodes to Facilitate Combustion Stability in Rocket Engines

R. Kaess [1], J. Braun [1],
[1] Airbus Safran Launchers, Ottobrunn, Germany

Airbus Safran Launchers is the market leader in Space Launch services. Rocket engines are among the most powerful machines that exist. The core of the rocket engine is the combustion chamber where in the case of liquid propellant rocket engines, fuel and oxidizer are injected, mixed and burnt and where, consequently, the energy release takes place. The hot combustion gases are accelerated in a ...

Characterization of a Tonpilz Transducer and Performance Analysis for a MEMS-Transducer Array

V. Vadde, and B. Lakshmi G
PESIT

In this paper, we develop and analyze a standard piezoacoustic Tonpilz-transducer model for underwater acoustics in Comsol by addressing the attendant piezoelectric and pressure acoustic multiphysics phenomena. Transducer properties that are studied and characterized are the center frequency, bandwidth, linearity, sensitivity, and noise figure. In an effort to miniaturize the transducer, a ...

Computational Acoustic Attenuation Performance of Helicoidal Resonators

W. Lapka
Poznan University of Technology
Poznan, Poland

This paper concerns the problem of obtaining proper acoustic attenuation performance through computations. COMSOL was used to solve acoustics systems with helicoidal resonators in the frequency domain. Based on the studies of insertion and transmission loss of helicoidal resonators, a high consistency between the results obtained by numerical calculations with experimental measurements was ...

Effects of Fluid and Structural Forces on the Dynamic Performance of High Speed Rotating Impellers.

C. Thiagarajan[1], G. Shenoy[2], B. S. Shenoy[3]
[1]ATOA Scientific Technologies Pvt Ltd, Whitefield, Bangalore, India.
[2]Department of Mechanical & Manufacturing Engineering, Manipal Institute of technology, Manipal, India
[3]Department of Aeronautical & Automobile Engineering, Manipal Institute of Technology, Manipal, India

Vibration and Dynamic performances of the rotating machinery are conventionally evaluated based on the dominant structural forces such as the centrifugal forces. The increase in rotational speed, miniaturization and performance, demands for improved and accurate evaluation of the vibration performance. The inclusion of coupled effects of fluid and centrifugal forces can contribute significantly ...

Development of a Reactive Silencer for Turbo Compressors

J. Smeulers[1], N. Gonzalez Diez[1]
[1]TNO, Delft, The Netherlands

Turbo compressors can generate high frequency tonal noise, causing nuisance in the environment. As the noise is radiated from the piping, a silencer is installed between the compressor and the pipe system. Commonly an absorption silencer is applied, which is a vessel that contains acoustic absorption material. Due to high flow velocities and vibrations the absorption material may be blown out ...

Numerical Study on Shear Horizontal Electromagnetic Acoustic Transducers for Generation of Ultrasonic Guided Waves for Absorber Tubes used in Concentrated Solar Plants - new

L. Cheng[1], A. Mohimi[1], M. Kogia[1], V. Kappatos[1], C. Selcuk[1], T.-H. Gan[1]
[1]Brunel Innovation Centre, Brunel University, Uxbridge, UK

Absorber tubes are one of the most critical components of parabolic trough Concentrated Solar Plants, which is very likely get damaged such as crack and mass loss. Therefore, the monitoring of their structural health via Non-Destructive Testing (NDT) techniques is regarded as essential for preventing them from being significantly defective and thereby reducing maintenance cost. Non-contact ...

Design of Electroacoustic Absorbers Using PID Control

H. Lissek, R. Boulandet, and M. Maugard
Ecole Polytechnique Federale de Lausanne
Lausanne, Switzerland

An \"electroacoustic absorber\" is a loudspeaker, used as an absorber of sound, which acoustic impedance can be varied by electrical means. This can be achieved either by plugging passive shunt electric networks at the loudspeaker terminals (“shunt loudspeakers”) or by feeding back the loudspeaker with a voltage proportional to acoustic quantities, such as sound pressure and diaphragm normal ...

A MEMS Condenser Microphone for Consumer Applications

S. L. Pinjare, V. S. Nagaraj, S. N. Savitha, S. Kesari, M. S. Sagar, and K. R. Roshan
Nitte Meenakshi Institute of Technology

The MEMS microphone is also called microphone chip or silicon microphone. The pressure sensitive diaphragm is etched directly into a silicon chip by MEMS techniques and is usually accompanied with integrated preamplifier. Most MEMS microphones are variants of the condenser microphone design. The MEMS microphone has been successfully fabricated and tested in an anechoic chamber. The microphone ...

Modeling and Testing of Carbon-Fiber Doubly-Resonant Underwater Acoustic Transducer

A. Morozov[1]
[1]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 ...

Support-Q Optimisation of a Trapped Mode Beam Resonator - new

T. H. Hanley[1], H. T. D. Grigg[1], B. J. Gallacher[1]
[1]Newcastle University, Newcastle-Upon-Tyne, UK

Introducing a disorder into a finite periodic oscillatory system induces the presence of a 'trapped mode': a mode in which the displacement field is localised to the region of the disorder. A main inhibitor to MEMS resonators achieving a high quality (Q) factor is energy radiation through the support to the substrate. The trapped modes present a way to tune this to a minimal value. An initial ...