Broadband diffuse field sound insulation of double layer metamaterial plates lined with porous material

2021 ◽  
Vol 119 (8) ◽  
pp. 084103
Author(s):  
Shuaixing Wang ◽  
Yong Xiao ◽  
Jiajia Guo ◽  
Hao Zhang ◽  
Jihong Wen
Keyword(s):  
Porous Material ◽  
Double Layer ◽  
Sound Insulation ◽  
Field Sound

Research of the Influence of Geometric Parameters of Rooms for Sound Insulation of Lightweight Partitions

2021 ◽  
pp. 37-47
Author(s):  
Д. В. Монич ◽  
И. В. Матвеева ◽  
П. А. Гребнев ◽  
Д. С. Кузьмин
Keyword(s):  
Noise Source ◽  
Experimental Studies ◽  
Sound Field ◽  
Sound Insulation ◽  
Mirror Reflection ◽  
Sound Waves ◽  
Good Convergence ◽  
Boundary Frequency ◽  
Field Sound ◽  
Wave Modes

Состояние проблемы. Звукоизоляция легких перегородок значительно зависит от места их установки в здании. Необходимы исследования структуры звукового поля в несоразмерных помещениях и анализ его влияния на звукоизоляцию легких ограждений. Результаты. Проведены натурные и лабораторные экспериментальные исследования звукоизоляции каркасно-обшивной перегородки, установленной в коридоре. Для случая соразмерного помещения получена хорошая сходимость результатов. Теоретически исследована структура звукового поля при зеркальном отражении звука (с использованием метода прослеживания лучей). Выполнены расчеты с получением распределений долей осевых, касательных и косых лучей в помещениях, расчеты уровней интенсивности звуковых волн, падающих на боковые стены и потолок коридора. Учитывалось положение источника шума относительно перегородки и других ограждений. Выводы. Пропорции помещений влияют на звукоизоляцию легких ограждений. В диапазоне ниже граничной частоты диффузности несоразмерного помещения с источником шума структура звукового поля неоднородная, звуковые лучи падают на ограждение неравномерно с различных направлений. Это приводит к уменьшению совпадений мод колебаний в воздухе и в ограждающей конструкции, частотная характеристика звукоизоляции ограждения имеет пикообразный вид. Statement of the problem. Sound insulation of lightweight partitions depends significantly on the place of installation in the building. It is necessary to study the structure of the sound field in disproportionate rooms and analyze its effect on the sound insulation of light enclosures. Results. Natural and laboratory experimental studies of the sound insulation of the frame partitions installed in the corridor were carried out. For the case of a commensurate room, good convergence of the results was obtained. The structure of the sound field with mirror reflection of sound has been theoretically investigated using the method of tracing of sound rays. Calculations were performed to obtain the distributions of the proportions of axial sound rays, tangential sound rays, oblique sound rays in the premises, and the calculations of the intensity levels of sound waves incident on the lightweight partition and other enclosures of the corridor. The position of the noise source relative to the lightweight partition and other enclosures of the corridor was taken into account. Conclusions. The proportions of the rooms affect the sound insulation of lightweight enclosures. The structure of the sound field of a disproportionate room with a noise source is non-uniform in the range below the boundary frequency of diffuse sound field. Sound rays fall on the lightweight partition unevenly from different directions. This leads to a decrease in the coincidence of wave modes in the air and wave modes in the lightweight partition. The frequency characteristic of the sound insulation of the lightweight partition has a peak-like appearance.

Research and Application of Building Enclosing Structure Used in Equipment Noise Control

2013 ◽  
Vol 423-426 ◽  
pp. 1272-1278
Author(s):  
Nan Xu
Keyword(s):  
Porous Material ◽  
Sound Absorption ◽  
Noise Control ◽  
Building Envelope ◽  
Sound Insulation ◽  
Hard Material ◽  
Noise Elimination ◽  
Control Engineering ◽  
Airborne Sound ◽  
Properties Of Materials

Porous material has a function of sound absorption, dense hard material can prevent the spread of airborne sound. The building envelope which is made up of different properties of materials, with good effects on sound insulation, sound absorption and noise elimination, can be widely used in noise control engineering.

A Simplified Method for Calculating Multilayer Sound Insulation with Layers of Fibrous Porous Material

2018 ◽  
Vol 64 (5) ◽  
pp. 643-650 ◽  
Author(s):  
L. R. Yablonik
Keyword(s):  
Porous Material ◽  
Sound Insulation ◽  
Simplified Method

Design of the Sound Insulation Chamber for Stored Grain Insect Sound Detection

2012 ◽  
Vol 220-223 ◽  
pp. 1598-1601 ◽  
Author(s):  
Sen Lin Geng ◽  
Fang Ju Li
Keyword(s):  
Double Layer ◽  
Ambient Noise ◽  
Outer Wall ◽  
Wall Material ◽  
Sound Insulation ◽  
Stored Grain ◽  
Layer Spacing ◽  
Average Spacing ◽  
Sound Detection ◽  
Absorbing Material

A six cubic meter sound insulation chamber is designed based on the principle of double-layer wall sound insulating and porous absorption with the characteristics of stored grain insect action sound. With 3 mm thick plywood as wall material, double - layer spacing 0.08 m, the outer wall being bored, each aperture 1mm, average spacing 1.5 cm, and the hard sound-absorbing material being filled in the two layers, a quasi - double layer perforated structure is built. The ambient noise is uniformly insulated between 125Hz and 2000Hz, and the average sound insulation is about 22dB, and it meets requirements of stored grain insect action sound for the spectrum and SPL. The result shows that the sound insulation chamber has the advantages of small size, economy, and good sound insulation effects.

Water movement through a swelling material

Soil Research ◽  
1965 ◽  
Vol 3 (1) ◽  
pp. 11 ◽  
Author(s):  
AV Blackmore ◽  
TJ Marshall
Keyword(s):  
Hydrostatic Pressure ◽  
Hydraulic Conductivity ◽  
Pressure Drop ◽  
Porous Material ◽  
Double Layer ◽  
Void Ratio ◽  
Electrolyte Concentration ◽  
Water Movement ◽  
Field Conditions ◽  
Sodium Montmorillonite

The effect of the drag of a fluid on the porous material through which it flows is examined for a swelling material. It is shown that, when equilibrium is established between drag and swelling in films of oriented sodium montmorillonite, there is a decrease in void ratio in the material in the direction of flow. This effect of drag increases with decreasing electrolyte concentration of the permeating solution, in accord with double-layer theory, and with increasing drop in hydrostatic pressure across the film. Hydraulic conductivity was found to increase with decreasing electrolyte concentration of the permeating solution, contrary to usual experience. The cause of this is considered to be the increase in spacing corresponding to decrease in concentration. Hydraulic conductivity of unconfined film at equilibrium was found to decrease with increasing drop in hydrostatic pressure across the film. An increase in the pressure drop causes a decrease in the spacing of the clay, particularly towards the base of the film, so that the hydraulic conductivity of the whole film is lowered. Consequently Darcy's law does not hold for these films. Implications for less ordered swelling systems are considered briefly. The effect of drag on soils under field conditions will ordinarily be negligible.

Application of Biot Theory in Analyzing the Sound Insulation Characteristic of Honeycomb Sandwich Panels

2007 ◽  
Vol 23 (1) ◽  
pp. 23-29
Author(s):  
C.-N. Wang ◽  
M.-J. Tang ◽  
C.-C. Tse
Keyword(s):  
Porous Material ◽  
Present Method ◽  
Transmission Loss ◽  
Sandwich Panels ◽  
Layered Media ◽  
Sound Insulation ◽  
Biot Theory ◽  
Honeycomb Core ◽  
Numerical Predictions ◽  
Honeycomb Sandwich

AbstractThe purpose of this paper is to apply Biot theory on analyzing honeycomb core to investigate the sound insulation characteristics of honeycomb sandwich panels. At first, the honeycomb core was regarded as a porous material and the sandwich panel is made of layered media. Thus Biot theory developed for fluid saturated porous material is adopted to analyze the waves propagated in honeycomb core. Then the transfer matrix for waves propagated between two ends of each panel is established. The combination of these related matrices can be conducted on evaluating the sound propagation characteristic in the layered media. The comparison of the transmission loss between the available experimental measurements and numerical predictions shows that the present method is reliable. With the present method, the numerical results reveal that the coincident frequency decreases apparently as the thickness of core increases. Therefore, the transmission loss is also increased in the analyzed frequency range. Further, the effect of core density and cell size are also investigated.

Study on sound insulation performance of double-layer perforated panel under normal incidence waves

2021 ◽  
Vol 174 ◽  
pp. 107785
Author(s):  
Zhongxu Kang ◽  
Ruixiang Song ◽  
Huijuan Zhang ◽  
Qiang Liu
Keyword(s):  
Double Layer ◽  
Normal Incidence ◽  
Sound Insulation ◽  
Insulation Performance

The Feasibility of Rock Wool Waste Utilisation in a Double-Layer Concrete Brick for Acoustic: A Conceptual Review

2020 ◽  
Vol 17 (2) ◽  
pp. 635-644
Author(s):  
Nur Zulzika Mohammad ◽  
Yap Zhen Shyong ◽  
Zaiton Haron ◽  
Mohammad Ismail ◽  
Azman Mohamed ◽  
...  
Keyword(s):  
Double Layer ◽  
Noise Pollution ◽  
High Energy ◽  
Sound Insulation ◽  
Insulation Material ◽  
Sound Barrier ◽  
Solid Media ◽  
Concrete Layer ◽  
Aerated Concrete ◽  
Rock Wool

Denser population in a city leads to a serious noise pollution problem. In order to control the ambient noise effectively, a sound insulation brick is desired. However, conventional bricks have poor sound barrier system and is made from unsustainable materials that consume high energy. Hence, this paper introduces a feasibility study on rock wool waste utilisation in a double-layer concrete brick (a combination of aerated concrete and solid concrete) as a potential technique to improve the sound barrier system in brick walls. Currently, rock wool waste is one of the synthetic wastes, which are massively dumped into the landfill by the industry or building demolition castoffs every year. However, rock wool waste has the potential to be recycled and reused as a sound insulation material because it still has the fibrous structural characteristic. Aerated concrete is generally known as an acoustic material; hence, this paper reviews on the implementation of rock wool waste in the aerated concrete layer to improve noise absorption performance. The optimum sound absorption and the thickness of aerated concrete were subsequently integrated with the solid media to transmit sound and indirectly improve the overall brick strength to form a double-layer concrete brick and facilitate the invention of sustainable bricks.

scholarly journals SETTING UP A PROBLEM OF AIR-BORNE SOUND IN-SULATION CALCULATION FOR DOUBLE LAYER MASSIVE ENCLOSURES ON THE BASE OF THE MODELS WITH THE CONCENTRATED PARAMETERS

2020 ◽  
Vol 16 (4) ◽  
pp. 111-120
Author(s):  
Arkadiy Zakharov ◽  
Ivan Saltikov
Keyword(s):  
Double Layer ◽  
Sound Propagation ◽  
Graph Drawing ◽  
Practical Interest ◽  
Single Layer ◽  
Mass Action ◽  
Sound Insulation ◽  
Mass Action Law ◽  
The One ◽  
Oscillation Movement

The calculation methods on the base of the concentrated parameters models, which were formed in the XX century, allowed to get simple and theoretically consistent solutions for the problems of one-layered building partitions sound insulation finding. The sound insulation estimation for the double-layered massive building partitions also is of scientific and practical interest, as double layer partitions are the particular case of the single layer enclosure's application. The concept of concentrated parameters includes the concentrated and the reduced masses, as well as the concentrated elasticity. The criteria for the object application as a specified kind of the concentrated parameters in the acoustical problems is the presence or the absence of the oscillation movement in it. The three calculation models with the application of the concentrated (discreet) parameters that to define the sound insulation of the massive double layer enclosures are given. The equations for sound insulation computation for one layer partition are represented. They were derived on the base of momentum law and energy conservation formulas under the continuity of energy flow conditions at the interface of different media. The three main paths of sound propagation from the room with the air-borne noise to the isolated room are shown. The two frequency range are separated on the way of the direct sound propagation: at the first, the surface density of the one of two layers and the air elasticity in the inter-layer gap influence on isolation; at the second one, the predominant role belongs to the summarized insulation by the "Mass Action Law" of the two layers. The indirect way's insulation is taken in account through the additional sound insulation graph drawing. The compound insulation curve is defined by the ways, where the sound energy transmittance is maximal at the standard frequency spectrum. The method of sound insulation calculation for the double layer partitions on the base of the concentrated parameters model application is revealed. As an example, the calculation of a prefabricated double layer inter-flat wall in the panel building was performed.

Wave-based modeling of sound insulation of a double layer finite panel with different infilling materials between two reverberant rooms

2018 ◽  
Vol 144 (3) ◽  
pp. 1847-1847
Author(s):  
Fangliang Chen ◽  
Yihe Huang ◽  
Tejav DeGanyar
Keyword(s):  
Double Layer ◽  
Sound Insulation
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