Glass Plates Noise Transmission Suppression by Means of Distributed Piezoelectric Composite Actuators Shunted by an Active Circuit
K. Novakova, P. Mokry
Research Centre for Special Optics and Optoelectronic Systems (TOPTEC), Institute of Plasma Physics, Academy of Sciences of the Czech Republic, Turnov, Czech Republic
Institute of Mechatronics and Computer Engineering, Technical University of Liberec, Liberec, Czech Republic
Glass windows represent a virtual sound source for buildings interior. It is very easy to make them vibrate by action of incident acoustic pressure wave. Therefore, non-negligible part of the wave is transmitted through the window. We propose and simulate a method based on the change of mechanical properties of the plate using flexible piezoelectric Macro Fiber Composite actuators distributed on ...
M. Hackert-Oschätzchen, R. Paul, M. Penzel, M. Zinecker, A. Schubert
Professorship Micromanufacturing Technology, Technische Universität Chemnitz, Chemnitz, Germany
Evaporative cooling is a promising cooling method for dissipating high heat fluxes in high power density applications. One possibility to enhance heat flux is a generation of microstructures into the cooler surface. This enlarges the cooler surface and systematically affects the fluid flow as well as the boiling process. In this study the geometric arrangement of cylindrical pin microstructures ...
R. De Luca[1,2], J. Fromageau, H.W. Chan, F. Marinozzi, J. Bamber
Institute of Cancer Research and Royal Marsden Hospital, Sutton, England, United Kingdom
Sapienza University of Rome, Dept. of Mechanical and Aerospace Engineering, Rome, Italy
Shear wave elastography is an innovative technique used in combination with the traditional ultrasound imaging to improve the specificity of cancer imaging. A two-dimensional finite element model (FEM), composed of realistic boundary conditions, was developed in COMSOL Multiphysics® to simulate the propagation of shear waves induced by an acoustic radiation force impulse (ARFI) in isotropic, ...
T. Suzuki, C. Holloway, S. Taylor
University College London, London, UK
Manual wheelchair users suffer shoulder pain and injury in the long term because of unconscious overuse. The ‘SENSEWHEEL’, which interposes three identical load cells between pushrim and rear wheel, measures the three components of pushing force Fx, Fy and Fz, and axial torque Tx applied at each load cell. Strain gauges were located on a diaphragm forming one face of the load cell. The ...
M. Yeoman, V. Sivasailam, A. Tomar
Continuum Blue Ltd., Ystrad Mynach, UK
Jaguar Land Rover Ltd, Coventry, UK
The design of windows and or other perforated structures which allow the free flow of air into & out of a building or system, while being fully soundproofed or attenuate certain frequencies is of great interest to architects and design engineers, where sound as a longitudinal wave, is difficult to separate it from its medium of propagation. In this work, we present the analysis of air ...
Evaluation of Efficiency Factors of Commercial Thermoelectric Materials Using COMSOL Multiphysics® Software
K. Cadien , S. Seif , T. Thundat ,
 Department of Chemical & Materials Engineering, University of Alberta, Edmonton, AB, Canada
We have developed single leg model using COMSOL Multiphysics® software to compute Φ of TE materials without using conventional ZT parameters. The Φ were calculated using parametric programming in PDE by using special probe to capture change in power (∆P), ΔT, and area (A), thus (Φ = ∆P/A*ΔT 2). The obtained results showed that the TE material with highest Φ when the temperatures are between 375 ...
K. Gladine , J. Soons , J. Dirckx 
 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.
Numerical Simulation of Acoustic Properties of Porous Metals under High Sound Pressure Level Conditions
B. Zhang , X. Wang , L. Ni 
 School of Mechanical Engineering, Ningxia University, China
The sound propagation and absorption properties in porous media under high sound pressure level conditions have been reported elsewhere. Also several analytical and semi-analytical solutions have been developed; however, these solutions are relatively complicated and the provided results are not accurate enough yet. In this work, the simulated results for the study of the sound absorption ...
S. D. Luise , L. M. Bueno ,
 ETH Zurich, Zurich, Switzerland
The DUNE experiment (http://www.dunescience.org/) is an international collaboration of more than 100 research institutes and universities (among them CERN and Fermilab) which is taking the challenge of building the next-generation experiment for the study of neutrino particles. The detector conceived to detect neutrinos consists of a gigantic cryogenic apparatus able to keep 700,000 tons of ...
唐旻 , 冯强强 , 董一琳 
近年来，三维系统级封装技术逐渐成为人们的关注焦点，是下一代集成电路封装设计最有发展潜力的实现方案。然而，热管理是系统级封装技术需解决的关键问题。图1是典型的系统级封装结构，包含堆叠芯片、硅通孔、封装基板、热界面材料以及多层凸点结构。若对该结构的所有细节进行建模，将会消耗巨大的计算资源，导致分析效率非常低下。因此，本论文将封装中的硅通孔层以及凸点层等复杂结构进行等效处理，提取它们在水平和垂直方向上的等效热导率以及等效比热容、等效密度等参数。例如，在建模过程中，采用 COMSOL Multiphysics® 传热模块对硅通孔层的水平方向等效热导率进行提取，边界设置如图2所示，通过仿真得到的热源端温度来推导等效热导率。类似地，垂直方向的等效热导率提取如图3所示。经过上述处理，可将封装中的硅通孔层以及凸点层等复杂结构等效为介质均匀的材料，然后再采用 COMSOL 进行整体封装结构的热仿真 ...