Prediction of acoustic wave transmission features of the multilayered plate constructions: A review

2021 ◽  
pp. 109963622199389
Author(s):  
MR Zarastvand ◽  
M Ghassabi ◽  
R Talebitooti
Keyword(s):  
Plane Wave ◽  
Acoustic Analysis ◽  
Sound Insulation ◽  
Acoustic Excitation ◽  
Acoustic Transmission ◽  
Multilayered Plate ◽  
Acoustic Performance ◽  
Control Techniques ◽  
Environmental Properties ◽  
Proper Theory

This study collects all of the existent papers in the field of acoustic transmission across multilayered plate constructions. Herewith, a comprehensive source is proposed wherein approximately 410 references are reviewed and described from the first [Formula: see text] to [Formula: see text]. In the first part, in addition to the presentation of a complete explanation about the importance of the acoustic analysis of these structures, appropriate formulations are also provided. Furthermore, an overview of the thematic correspondent is carried out. Since the type of material used in these constructions can be very important in sound insulation, the significance of this subject is remarked. The papers are then classified based on their acoustic excitation fields containing plane wave, diffuse, random, and point source. After analyzing the research approaches according to different environmental properties, the articles are ordered based on their boundaries as finite and infinite. To present reliable outcomes, it is necessary to investigate a proper theory proportional to the structure’s thickness. Herewith, this issue is also discussed in detail. The review is also expanded to focus on the different vibroacoustic solutions. Before concluding remarks, the authors' research works are presented wherein either optimization algorithms or control techniques improve the acoustic performance of these structures.

Research on the Insulation Performance of Sound-Isolating and Decoupled Tiles

2013 ◽  
Vol 457-458 ◽  
pp. 703-706 ◽  
Author(s):  
De Jin Qian ◽  
Xue Ren Wang ◽  
Xu Hong Miao
Keyword(s):  
Large Scale ◽  
Acoustic Radiation ◽  
Single Point ◽  
Mechanical Vibration ◽  
Sound Insulation ◽  
Acoustic Performance ◽  
Operating Modes ◽  
Insulation Effect ◽  
Vibration And Sound Radiation ◽  
Insulation Performance

The acoustic performance of sound-isolating and decoupled tiles is studied from macroscopic and microscopic. First, the sound absorption and reverse sound insulation performance of sound-isolating and decoupled tiles is studied based on laminated media; then the acoustic decoupling materials influence on acoustic radiation of double cylindrical shell underwater is studied, using a double-layer cylindrical structure of large-scale as experimental model .There are large amount of operating modes designed in this experiment, such as all laying, partial laying, laying and so on. The results show that sound-isolating and decoupled tiles not only have the effect of weakening the absorption of reflections, but also have reverse sound insulation effect, which increases as frequency increases; for single point mechanical vibration, the tiles can effectively inhibit vibration and sound radiation of high frequency in the double shell.

Sound insulation performance of pyramidal truss core sandwich structure with frame

2021 ◽  
pp. 109963622110288
Author(s):  
Yu-Zhou Wang ◽  
Li Ma
Keyword(s):  
Mechanical Properties ◽  
Sandwich Structure ◽  
Transmission Loss ◽  
Low Frequency ◽  
Sound Insulation ◽  
Geometrical Parameters ◽  
Acoustic Performance ◽  
Truss Core ◽  
Pyramidal Truss ◽  
Wave Angle

Recently, sandwich structures have been widely used in different fields because of their good mechanical properties, but these structures are weak in acoustic performance. In this paper, by combining pyramidal truss core sandwich structure with frame, a new structure is proposed with both good mechanical properties and excellent acoustic performance at low frequency. An analytical model of the pyramidal truss core sandwich structure with frame is developed to investigate the sound transmission loss (STL) performance. Finite element method (FEM) is also used to investigate the STL performance at low frequency. The effects of the incident wave angle and the geometrical parameters on the STL of the structure are discussed.

A REVIEW OF METHODS FOR HYDRO-ACOUSTIC ANALYSIS OF NON-CAVITATING MARINE PROPELLERS

2021 ◽  
Vol 161 (A3) ◽  
Author(s):  
Abhishek Kumar Tewari ◽  
R Vijayakumar
Keyword(s):  
Marine Mammals ◽  
Acoustic Analysis ◽  
Open Water ◽  
Acoustic Analogy ◽  
Hydrodynamic Analysis ◽  
Radiated Noise ◽  
Acoustic Performance ◽  
Marine Propellers ◽  
Potential Contributor ◽  
Ocean Environment

Underwater Radiated Noise (URN) emanating from surface and underwater marine platforms has become a significant concern for all the Nations in view of the global requirement to minimise the increasing adverse impact on marine mammals and fishes and maintain ecological balance in the ‘Silent’ ocean environment. Ambient noise level in the sea, in 10 to 300 Hz frequency band, has increased by 20 to 30 dB due to shipping (Wittekind, 2009). Marine propeller (in non- cavitating and cavitating regime) is a potential contributor to the ships noise and a lot of scientific research has been undertaken and considerable progress has been achieved in estimating the hydro-acoustic performance of marine propellers. In light of this, the scope of this paper is to review and critically examine the various methods used for estimating the hydro-acoustic performance of marine propellers, particularly in the non-cavitating regime, over the past many years. This review paper brings out the details, applicability, merits and demerits of various methods, extrapolation laws to obtain full scale results, scientific conclusion of all the know-how on this subject and the scope of further research as perceived by the authors. This paper also presents a numerical methodology to estimate the noise radiated by a DTMB 4119 model propeller in the non-cavitating regime in open water condition. The hydrodynamic analysis of the propeller was performed using commercial CFD software STARCCM+, closure was achieved using standard k-ε turbulence model and hydro-acoustic predictions have been performed using FWH acoustic analogy. The results compare very well with the published literature.

scholarly journals Proposal of an Assessment Method of the Impact Sound Insulation of Lightweight Floors

Buildings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 13
Author(s):  
Łukasz Nowotny ◽  
Jacek Nurzyński
Keyword(s):  
Sound Pressure ◽  
Residential Buildings ◽  
Assessment Method ◽  
Sustainable Construction ◽  
Sound Insulation ◽  
Indicator Values ◽  
Floor Covering ◽  
Acoustic Performance ◽  
Quality Rating ◽  
The Impact

Lightweight floors are in line with a sustainable construction concept and have become increasingly popular in residential buildings. The acoustic performance of such floors plays a pivotal role in the overall building quality rating. There is, however, no clear and complete method to predict their impact sound insulation. A new approximation method and new acoustic indicators—equivalent weighted normalized impact sound pressure levels for lightweight floors—are proposed and outlined in this article. The prediction procedure and indicator values were initially validated on the basis of laboratory measurements taken for different lightweight floors with the same well-defined floor covering. These preliminary analyses and comparisons show that the proposed method is promising and should be fully developed on the basis of further research.

Unsteady Acoustic Forcing on an Impeller Due to Coupled Blade Row Interactions

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Simon K. Richards ◽  
Kishore Ramakrishnan ◽  
Chingwei M. Shieh ◽  
François Moyroud ◽  
Alain Picavet ◽  
...  
Keyword(s):  
Centrifugal Compressor ◽  
Oil And Gas ◽  
Acoustic Analysis ◽  
Pressure Ratio ◽  
Centrifugal Impeller ◽  
Acoustic Excitation ◽  
Wake Interaction ◽  
Blade Row ◽  
Acoustic Forcing ◽  
Return Channel

This article contains an investigation of the unsteady acoustic forcing on a centrifugal impeller due to coupled blade row interactions. Selected results from an aeromechanical test campaign on a GE Oil and Gas centrifugal compressor stage with a vaneless diffuser are presented. The most commonly encountered sources of impeller excitation due to upstream wake interaction were identified and observed in the testing campaign. A 30/rev excitation corresponding to the sum of upstream and downstream vane counts caused significant trailing edge vibratory stress amplitudes. Due to the large spacing between the impeller and the return channel vanes, this 30/rev excitation was suspected to be caused by an aero-acoustic excitation rather than a potential disturbance. The origin of this aero-acoustic excitation was deduced from an acoustic analysis of the unsteady compressor flow derived from CFD. The analysis revealed a complex excitation mechanism caused by impeller interaction with the upstream vane row wakes and subsequent acoustic wave reflection from the downstream return channel vanes. The findings show it is important to account for aero-acoustic forcing in the aeromechanical design of low pressure ratio centrifugal compressor stages.

scholarly journals Lightweight ventilated façade: Acoustic performance in laboratory conditions, analysing the impact of controlled ventilation variations on airborne sound insulation

2020 ◽  
Vol 27 (4) ◽  
pp. 367-379
Author(s):  
Joan Lluis Zamora Mestre ◽  
Andrea Niampira
Keyword(s):  
Sound Insulation ◽  
Air Cavity ◽  
Acoustic Performance ◽  
Controlled Ventilation ◽  
Laboratory Conditions ◽  
Airborne Sound ◽  
Cavity Thickness ◽  
Ventilated Facade ◽  
The Impact ◽  
Real Building

The use of double-sheet enclosures with an intermediate non-ventilated air cavity guarantees a higher airborne sound insulation. The insulation advantages depend on air tightness and the placement of sound absorbing material in the air cavity. The lightweight ventilated façade is a system constructed by the addition of an external light cladding on a heavy single wall to establish an intermediate air cavity. This air cavity can be ventilated under controlled cooling effects, because of Sun’s radiation, and to reduce the risk of dampness caused by rainwater. Owing to this ventilation, acoustic insulation of the lightweight ventilated façade could be less effective. However, some authors indicate that air cavity moderate ventilation does not necessarily lead to a significant reduction in the airborne sound insulation. The authors previously verified this situation in a real building where the existing façade of masonry walls was transformed into a lightweight ventilated façade. The preliminary results indicate the acoustic benefits can be compatible with the hygrothermal benefits derived from controlled ventilation. This article presents the next step, the evaluation of the lightweight ventilated façade acoustic performance under laboratory conditions to revalidate the previous results and refining aspects as the air cavity thickness or the state of openings ventilation. The main results obtained indicate that the airborne sound insulation in laboratory is aligned with the previous results in a real building. Air cavity thickness from 110 to 175 mm and ventilation openings from 0% to 3.84% of the façade area does not lead to a significant reduction in the airborne sound insulation.

scholarly journals Indoor Acoustic Comfort Provided by an Innovative Preconstructed Wall Module: Sound Insulation Performance Analysis

2020 ◽  
Vol 12 (20) ◽  
pp. 8666
Author(s):  
Dimitra Tsirigoti ◽  
Christina Giarma ◽  
Katerina Tsikaloudaki
Keyword(s):  
Energy Performance ◽  
Bearing Steel ◽  
Sound Insulation ◽  
Frequency Noise ◽  
Indoor Environmental Quality ◽  
Exterior Surface ◽  
Acoustic Performance ◽  
Insulation Materials ◽  
Acoustic Comfort ◽  
Insulation Performance

The complicated nature of indoor environmental quality (IEQ) (thermal, visual, acoustic comfort, etc.) dictates a multi-fold approach for desirable IEQ levels to be achieved. The improvement of building shells’ thermal performance, imposed by the constantly revised buildings’ energy performance regulations, does not necessarily guarantee the upgrade of all IEQ-related aspects, such as the construction’s acoustic quality, as most of the commonly used insulation materials are characterized by their low acoustic performance properties. From this perspective the SUstainable PReconstructed Innovative Module (SU.PR.I.M.) research project investigates a new, innovative preconstructed building module with advanced characteristics, which can, among other features, provide a high quality of acoustic performance in the indoor space. The module consists of two reinforced concrete vertical panels, between which the load bearing steel profiles are positioned. In the cavity and at the exterior surface of the panel there is a layer of thermal insulation. For the scope of the analysis, different external finishing surfaces are considered, including cladding with slate and brick, and different cavity insulation materials are examined. The addition of Phase Change Materials (PCM) in different mix proportions in the interior concrete panel is also examined. For the calculation of the sound insulation performance of the building module the INSUL 9.0 software is used. The results were validated through an experimental measurement in the laboratory in order to test the consistency of the values obtained. The results indicate that the examined preconstructed module can cover the sound insulation national regulation’s performance limits, but the implementation of such panels in building constructions should be carefully considered in case of lower frequency noise environments.

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