Maltsev N.E. «Numerical Implementation of Huygens Principle for Scattering from a Smooth Ideal Surface» Акустический журнал, 65, № 5, с. pp. 467-470 (2019)

In 1678 Huygens formulated a principle postulating that each point on a wave front acts as a point source emitting a spherical wave which travels with a local velocity. The field at a given point some time later is then the sum of the fields of each of these point sources. In this article a numerical method is presented for 2D problems of sound propagation and scattering, conforming that physical assumptions.

Ahmad Iftikhar, Hassan Adnan, Anjum Muneeb Ullah, Malik Sohail, Ali Tashfeen «Ambient Acoustic Energy Harvesting using Two Connected Resonators with Piezoelement for Wireless Distributed Sensor Network» Акустический журнал, 65, № 5, с. pp. 471-477 (2019)

In this article, an acoustic energy harvester (AEH) is conceptualized, designed, fabricated and tested. The developed AEH (DAEH) consists of two Helmholtz cavities (HCs) and a commercially available piezoelement. The HCs were fabricated from Teflon material using conventional machining operations. An indigenous test bench for in-lab characterization of DAEH has also been developed. Various experiments were performed to experimentally record the frequency response function, loading and power characteristics. Additionally, the in-lab and open-air characterization of the DAEH is also reported. Furthermore, the proposed prototype of DAEH is compared on the basis of various benchmarks with the prototypes available in the literature. The experimental results indicate a maximum power density of 32.7 μW/cm³ at 130 dB.

Dunai L., Lengua I., Iglesias M., Peris-Fajarnés G. «Buffeting-Noise Evaluation in Passenger Vehicle BMV 530d» Акустический журнал, 65, № 5, с. pp. 578-582 (2019)

In this paper we exhibit the results and evaluation of the buffeting-noise effect in a BMW 530d model vehicle. The buffeting noise was studied in real measurement conditions in an outdoors highway at different speeds. We evaluate different listening positions inside the vehicle to demonstrate that the buffeting-noise effect is independent from the listener position.

Ma Huayuan, Long Yuan, Zhong Mingshou, Li Xinghua, Xie Quanmin «Study on Ground Vibration Mode of Physical Explosion of High Pressure Natural Gas Pipeline» Акустический журнал, 65, № 5, с. pp. 583-592 (2019)

In this paper, an explosion experiment was carried out on the OD1219mm-X90-12Mpa natural gas pipeline to study the vibration hazard. Based on a series of experiments, the spatial distribution of the vibration energy was studied. The vibration distribution field was drawn by interpolation method based on re-harmonic equation and it was found that the field was non-circular symmetry. Through in-depth research, it was preliminarily proved that the vibration field had interference characteristics, which was caused by the special vibration source of the pipeline explosion. There was a significant difference in the frequency components between the interference strengthened region and the weakened region. The results shown that the strengthening effect of the interference in the 90° and 30° direction should be taken into account when evaluating the damage scope of the explosion accident. Research provided reference for safety design of parallel pipelines and buildings.