W. R. Kampinga, and Y. H. Wijnant
Reden, Hengelo, Netherlands
University of Twente, Enschede, Netherlands
Three efficient alternatives to the model in COMSOL’s thermoacoustics interface are presented. The higher efficiency of these models are explained from theory and are demonstrated by means of two examples.
C. Thiagarajan, G. Shenoy, B. S. Shenoy
ATOA Scientific Technologies Pvt Ltd, Whitefield, Bangalore, India.
Department of Mechanical & Manufacturing Engineering, Manipal Institute of technology, Manipal, India
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 ...
Y. Li, T.C. Lieuwen, J. Zhou, H. Cao
Zhengzhou University, Zhengzhou City, Henan Province, China
Georgia Institute of Technology, Atlanta, GA
One can hardly get the exact analytic solution of a full time-dependent convection-diffusion equation, for describing the dynamics of a non-premixed flamelet. The analytic solution of the linearized form with such a model was studied by MATLAB®. And also, a numerical computation was made with the linearization model in COMSOL Multiphysics® software, to provide a perfect accordance with the ...
N. R. Mahesh, and P. Nair
SSN College of Engineering
Tamil Nadu, India
Acoustic metamaterials are structured materials of negative mass density or negative bulk-modulus or both of them. Materials are tailored in sub-wavelength dimensions so as to get these negative properties. This paper compares the result of an experimental investigation of acoustic metamaterial with negative bulk-modulus to its COMSOL modeling. The resonance characteristics of single ...
T. Kaufmann, F. Kassubek, D. Pape , M. Lenner
ABB Corporate Research, Baden-Dättwil, Switzerland
Lamb waves are elastic waves propagating in free solid plates. In the case of plates loaded with a fluid, the equations describing these waves have to be modified to include the effects of the fluid. In our work we have tackled this problem using COMSOL Multiphysics®. We have used the two-dimensional plane strain model of the solid mechanics interface to calculate the eigenmodes of the coupled ...
张秀海 , 王琼 , 屈治国 ,
引言 多孔材料能够吸收大量声能且只反射少量声波，因此具有良好的吸声性能而被广泛地用于噪声的控制。梯度多孔材料吸声性能的实验研究已经有所开展，但相应的数值研究却很鲜见。 COMSOL Multiphysics® 的使用 本文分别用3层和6层孔隙度呈等差数列的多孔玻璃丝组合成梯度多孔玻璃丝（图1为由3层不同孔隙度的多孔玻璃丝组成的梯度多孔玻璃丝，空气区域为宽W、高H的矩形，余下区域为多孔玻璃丝区域），并根据 DBM 模型采用 COMSOL Multiphysics® 模拟组合成的梯度多孔玻璃丝的吸声性能。 结果 由图2，梯度多孔玻璃丝（3层）与相同厚度、相同孔隙度普通多孔玻璃丝比较，前者在声音处于低频段情况吸声效果有明显的改善。梯度多孔玻璃丝（3层）和梯度多孔玻璃丝（6层）的吸声系数如图3所示，在 100Hz-400Hz 的低频段，两者吸声系数有较大的误差。 结论 ...
Poznan University of Technology
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 ...
所谓近场声学，是相对于远场声学而言。传统的声学理论，通常只研究远离光源或者远离物体的声场分布，一般统称为远场声学。远场声学在原理上存在着一个远场衍射极限，限制了利用远场光学原理进行显微和其它光学应用时的最小分辨尺寸和最小标记尺寸。而近场声学则研究距离光源或物体一个波长范围内的光场分布。在近场声学研究领域，远场衍射极限被打破，分辨率极限在原理上不再受到任何限制，可以无限地小，从而基于近场声学原理可以提高显微成像与其它光学应用时的光学分辨率。 声学超材料自问世之日起就受到了国内外科学家们的广泛追捧，在很多领域都可以看到其踪迹，以声子晶体为代表的声超材料具有很多天然材料所不具备的声学特性，为声学信号处理带来了很多创新的思路和途径。 声超材料的突出特点在于采用尺寸远小于入射波长的人工结构构建出等效参数，利用等效参数实现“小尺寸结构调控大尺寸波长”的目的。 ...
Surface Acoustic Wave Scattering Matrix Evaluation Using COMSOL Multiphysics®: Application to Surface Acoustic Wave Transmission Through 2D Surface Phononic Crystal
S. Yankin[1,2], A. Talbi, V. Preobrazhensky[1,3], P. Pernod, O. Bou Matar, A. Pavlova
 Joint International Laboratory LICS/LEMAC, IEMN UMR CNRS 8520, EC Lille, Villeneuve d'Ascq, France
 Saratov State University, Saratov, Russia
 Wave Research Center, Russian Academy of Sciences, Moscow, Russia
This contribution is dedicated to numerical analysis of SAW propagation though 2D surface phononic crystal (PnC) and FE method is nowadays one of most common tool for such calculation. The device under investigation consists of two dispersive IDT and lattice of ferromagnetic pillars realized on 128°YX LiNbO3. In addition to dispersion curves calculations this work describes the results of ...
Karthi Pradeep, G. Suresh, V. Natarajan,
National Institute of Technology, Tiruchirappalli, Kerala, India
Naval Physical & Oceanographic Laboratory (NPOL), Kochi, Kerala, India
A Helmholtz resonator type acoustic sensor has been designed using analytical method and finite element modeling software, COMSOL Multiphysics®. The acoustic sensor is an aluminium double frustum, hour glass, shaped with the resonator at the bottom and an acoustic horn above to amplify the incoming acoustic signal. The horn provides a broad amplification of the incoming acoustic signal while the ...