Jianing Zhang^1,2, Ziying Yu¹, Hengxu Yang^1,2, Ming Wu¹, Jun Yang^1,2,*

Sound & Vibration, Vol.53, No.2, pp. 2-15, 2019, DOI:10.32604/sv.2019.03783

Abstract Ultrasound can be used as a carrier to realize wireless communication to and from a metal-enclosed space, which has the characteristics such as immunity to the electromagnetic shielding effect and non-destructive penetration of metal obstacles. This paper firstly reviews the previous studies in the field of ultrasonic wireless communication through metal barriers, and summarizes their achievements and the existing problems. Secondly, an overview of the research methods involved in studying the characteristic of acoustic-electric channel is presented, and the principles are introduced for the actual measurement method, equivalent circuit method, ABCD parameter method, finite element analysis method and time-domain finite… More >

Wen Zhao, Dongxing Mao^*, Zaixiu Jiang

Sound & Vibration, Vol.53, No.1, pp. 37-46, 2019, DOI:10.32604/sv.2019.04368

Abstract In order to analyze the effect of the background flow on the sound prediction of fine-scale turbulence noise, the sound spectra from static and flow environments are compared. It turns out that, the two methods can obtain similar predictions not only at 90 deg to the jet axis but also at mid- and high frequencies in other directions. The discrepancies of predictions from the two environments show that the effect of the jet flow on the sound propagation is related to low frequencies in the downstream and upstream directions. It is noted that there is an obvious advantage of computational… More >

Jianliang Jiang¹, Bosun Xie^1,2,*, Haiming Mai¹

Sound & Vibration, Vol.53, No.1, pp. 25-36, 2019, DOI:10.32604/sv.2019.04259

Abstract Ambisonics is a series of spatial sound reproduction system based on spatial harmonics decomposition and each order approximation of sound field. Ambisonics signals are originally intended for loudspeakers reproduction. By using head-related transfer functions (HRTFs) filters, binaural Ambisonics converts the Ambisonics signals for static or dynamic headphone reproduction. In present work, the performances of static and dynamic binaural Ambisonics reproduction are evaluated and compared. The mean binaural pressure errors across target source directions are first analyzed. Then a virtual source localization experiment is conducted, and the localization performances are evaluated by analyzing the percentages of front-back and up-down confusion, the… More >

Rahul Kumar Sharma^*1, V. Sugumaran¹, Hemantha Kumar², Amarnath M³

Structural Durability & Health Monitoring, Vol.11, No.1, pp. 1-16, 2017, DOI:10.3970/sdhm.2017.012.001

Abstract Most of the machineries in small or large scale industry have rotating element supported by bearings for rigid support and accurate movement. For proper functioning of machinery, condition monitoring of the bearing is very important. In present study sound signal is used to continuously monitor bearing health as sound signals of rotating machineries carry dynamic information of components. There are numerous studies in literature that are reporting superiority of vibration signal of bearing fault diagnosis. However, there are very few studies done using sound signal. The cost associated with condition monitoring using sound signal (Microphone) is less than the cost… More >

L. Gaul, M. Fischer¹, U. Nackenhorst²

CMES-Computer Modeling in Engineering & Sciences, Vol.3, No.6, pp. 815-824, 2002, DOI:10.3970/cmes.2002.003.815

Abstract A sequential FEM--BEM approach is employed to calculate the dynamic behavior and sound radiation of rotating wheels. The equations of motion for the wheel are developed in the frame of an Arbitrary Eulerian Lagrangian description with a time-independent formulation for steady state rolling and a spatial description of vibrations. The noise radiation caused by the vibration modes is computed by the symmetric hybrid boundary element method. More >

Mingchao Cai, Chun Yang, Mehmet H. Kural, Richard Bach, David Muccigrosso, Deshan Yang, Jie Zheng, Kristen L. Billiar, Dalin Tang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.4, pp. 97-104, 2011, DOI:10.3970/icces.2011.019.097

Abstract Image-based computational modeling has been introduced for vulnerable atherosclerotic plaques to identify critical mechanical conditions which may be used for better risk assessment and rupture predictions. In vivo patient-specific coronary plaque models are lagging due to limitations on non-invasive image resolution, flow data, and vessel material properties. We propose a procedure where intravascular ultrasound (IVUS) imaging, biaxial mechanical testing and computational modeling are combined together to acquire better and more complete plaque data and make more accurate plaque vulnerability assessment and predictions. More >

D. I. Fotiadis¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.5, No.2, pp. 85-92, 2008, DOI:10.3970/icces.2008.005.085

Abstract Quantitative ultrasound has attracted significant interest in the evaluation of bone fracture healing. Animal and clinical studies have demonstrated that the propagation velocity across fractured bones can be used as an indicator of healing. Researchers have recently employed computational methods for modeling wave propagation in bones aiming to gain insight into the underlying mechanisms of wave propagation and to further enhance the monitoring capabilities of ultrasound. In this paper we review the computational studies of ultrasound wave propagation in intact and healing bones. More >

J. António¹ , A. Tadeu¹, L. Godinho

The International Conference on Computational & Experimental Engineering and Sciences, Vol.3, No.3, pp. 157-162, 2007, DOI:10.3970/icces.2007.003.157

Abstract A frequency dependent formulation based on the Method of Fundamental Solutions (MFS) is used to simulate the sound wave propagation in a 3D acoustic space. This solution is approximated by a linear combination of fundamental solutions generated by virtual sources placed outside the domain in order to avoid singularities. The coating materials can be assumed to be absorbent. This is achieved in the model prescribing the impedance that is defined as a function of the absorption coefficient. The model is first verified against analytical solutions, provided by the image source technique for a parallelepiped room bounded by rigid walls. The… More >

Hong-Ching Her¹, Jin H. Huang¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.2, pp. 55-56, 2009, DOI:10.3970/icces.2009.010.055

Abstract To play melodious sound, a microspeaker in a cellular phone needs to generate wide, smooth sound-pressure-level distribution over the mid-frequency spectrum, ranging from 600 Hz to 10 kHz. In this paper, parametric study is carried out to investigate the effect of various design parameters on the sound-pressure-level distribution. The electro-mechano-acoustical analogous approach is applied to simulate the sound-pressure-level. Also, experiments are conducted for verifications. Discussions about each role of the design parameters are addressed to improve the overall sound-pressure-level performance over the mid-frequency spectrum. More >

Shijun Zhao^1,2, Xiaoying Chen^1,3,*, Xiaolei Wang¹, Wenming Ji¹, Zhonghua Dai⁴

Journal of Quantum Computing, Vol.1, No.1, pp. 29-39, 2019, DOI:10.32604/jqc.2019.06112

Abstract The condensation process of dew droplets is influenced by many factors. A dew point condensation image observation system was built to improve the response speed of dew point detector under different measuring conditions. The basic mechanism of dew drop condensation growth was studied and the influence of various factors on the dew drop growth rate were analyzed. And the accuracy of the influence results was verified based on the improved Hough transform circle detection. The results show that the growth rate of dew droplets is affected by ambient temperature, dew point temperature, mirror temperature and air velocity. The observed variation… More >