Effect of Manufacturing Defects in the Form of Internal Leakages on the Acoustic Performance of Mufflers
D. Neihguk, A. Prasad 
 Mahindra & Mahindra Ltd, Chengalpattu, Tamil Nadu, India
The presence of manufacturing defects in the form of incomplete welding and missing perforated holes leads to internal leakages in mufflers. This results into unintended acoustic impedance modifications as well as the Herschel-Quincke effect. The narrow region acoustics model of COMSOL Multiphysics® software is used to simulate the thermoviscous losses associated with the leakages. The ...
Finite Element Model for Simulating the Inspection of Steel Tubes Using Electromagnetic Acoustic Transducers - new
P. Sun, X. Ding, X. Wu, M. Cong
School of Mechanical Science & Engineering, Huazhong University of Science and Technology, Wuhan, China
Steel tubes are widely used in industries. In order to ensure the safety and reliability of industrial processes, electromagnetic acoustic transducers (EMATs) based guided wave technology has been developed for inspecting stainless steel tubes regularly. Theoretical models and finite element modes have been built to investigate the EMAT technology. However, existing models mainly focused on ...
G. Vigna, L. Spicci
Esaote SPA, Florence, Italy
Self-heating is a problem to consider for Ultrasound Imaging probes. Since the probe is in contact with the skin, it’s necessary to find a solution to lower the front face temperature in order to avoid patient discomfort, even at the most demanding operating condition. One solution consists in the design of a device that drains the heat from the front to the rear of the transducer, where a ...
G.D. Cole, M. Aspelmeyer, and I. Wilson-Rae
University of Vienna, Vienna, Austria
Technical University Munich, Munich, Germany
Micro-and nanoscale mechanical resonators have recently emerged as ubiquitous devices for use in advanced technological applications, for example in mobile communications and inertial sensors, and as novel tools for fundamental scientific endeavors. We report a significant advancement towards understanding and controlling support-induced losses through the demonstration of an efficient numerical ...
C. R. Pérez , J. J. Santiago-Avilés ,
 Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, USA
 Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, USA
Sensorineural hearing loss is the most common sensory deficit in the world, and within this category damage or loss of the primary sensory cells of the inner ear, known as hair cells is the most common cause . Partial hearing loss is addressed by the use of hearing aids, electronic devices that greatly amplify sound directly into the user's ear, but for more severe cases cochlear implants are ...
S.L. Firebaugh, F. Roignant, and E.A. Terray
United States Naval Academy, Annapolis, Maryland, USA
Polytechnique Nantes, Nantes, France
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 ...
A Study into the Acoustic and Vibrational Effects of Carbon Fiber Reinforced Plastic as a Sole Manufacturing Material for Acoustic Guitars
J. O'Donnell, G. McRobbie
University of the West of Scotland, Paisley, Scotland, United Kingdom
This study will research a modern design of acoustic guitar by analysis of the vibrational modes. The guitar that will undergo testing has been provided by Emerald Guitars and is solely constructed using Carbon Fiber Reinforced Plastic (CFRP). With the use of COMSOL Multiphysics© the soundboard of the guitar will be simulated and analysis will be carried out to determine the first 10 ...
T. H. Hanley, H. T. D. Grigg, B. J. Gallacher
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 ...
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 ...
M. Cobianchi and R. Magalotti
 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 ...