scholarly journals Prediction of Noise Performance of Ro-Ro Passenger Ship by the Hybrid Statistical Energy Analysi

2018 ◽  
Vol 2 (Special edition 2) ◽  
pp. 29-45
Author(s):  
Nikola Vladimir ◽  
Ivan Lončar ◽  
Ivica Aničić ◽  
Ivo Senjanović
Keyword(s):  
Noise Source ◽  
Noise Analysis ◽  
Noise Model ◽  
Design Parameters ◽  
Sound Insulation ◽  
Noise Prediction ◽  
Noise Performance ◽  
Noise Levels ◽  
Technical Data ◽  
Passenger Ship

Noise prediction on board Ro-Ro passenger ship with a capacity of 145 cars and 600 passengers has been performed by means of the hybrid Statistical Energy Analysis (SEA). A general commercial noise analysis software Designer-NOISE is used. Basic issues related to noise on board ships are described, with particular emphasis to regulatory framework. An outline of the used software is presented together with ship technical data and noise source overview. Noise model is described in details and results are presented for selected compartments both without and with sound insulation. In addition to standard noise prediction output, a sensitivity analysis of noise levels with respect to some design parameters (wall thickness, insulation type and thickness, etc.) has been performed. Finally, conclusions on noise performance of a ship are drawn.

scholarly journals A Modularized Noise Analysis Method with Its Application in Readout Circuit Design

VLSI Design ◽  
2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Xiao Wang ◽  
Zelin Shi ◽  
Baoshu Xu
Keyword(s):  
Integrated Circuit ◽  
Transfer Functions ◽  
Noise Source ◽  
Noise Analysis ◽  
Noise Model ◽  
Analysis Method ◽  
Noise Performance ◽  
Subthreshold Region ◽  
Readout Integrated Circuit ◽  
Output Noise

A readout integrated circuit (ROIC) is a crucial part that determines the quality of imaging. In order to analyze the noise of a ROIC with distinct illustration of each noise source transferring, a modularized noise analysis method is proposed whose application is applied for a ROIC cell, where all the MOSFETs are optimized in subthreshold region, leading to the power dissipation 2.8 μW. The modularized noise analysis begins with the noise model built using transfer functions and afterwards presents the transfer process of noise in the form of matrix, through which we can describe the contribution of each noise source to the whole output noise clearly, besides optimizing the values of key components. The optimal noise performance is obtained under the limitation of layout area less than 30 μm × 30 μm, resulting in that the integration capacitor should be selected as 0.74 pF to achieve an optimal noise performance, the whole output noise reaching the minimum value at 74.1 μV. In the end transient simulations utilizing Verilog-A are carried out for comparisons. The results showing good agreement verify the feasibility of the method presented through matrix.

scholarly journals Background noise analysis in urban airport surroundings of Brazilian cities, Congonhas Airport, São Paulo

2016 ◽  
Vol 50 (0) ◽  
Author(s):  
Fabio Scatolini ◽  
Cláudio Jorge Pinto Alves
Keyword(s):  
Traffic Control ◽  
Background Noise ◽  
Noise Analysis ◽  
Exposure Level ◽  
Noise Levels ◽  
Sound Exposure ◽  
Operational Characteristics ◽  
Data Compilation ◽  
Noise Measurements ◽  
Noise Data

ABSTRACT OBJECTIVE To perform a quantitative analysis of the background noise at Congonhas Airport surroundings based on large sampling and measurements with no interruption. METHODS Measuring sites were chosen from 62 and 72 DNL (day-night-level) noise contours, in urban sites compatible with residential use. Fifteen sites were monitored for at least 168 hours without interruption or seven consecutive days. Data compilation was based on cross-reference between noise measurements and air traffic control records, and results were validated by airport meteorological reports. Preliminary diagnoses were established using the standard NBR-13368. Background noise values were calculated based on the Sound Exposure Level (SEL). Statistic parameters were calculated in one-hour intervals. RESULTS Only four of the fifteen sites assessed presented aircraft operations as a clear cause for the noise annoyance. Even so, it is possible to detect background noise levels above regulation limits during periods of low airport activity or when it closes at night. CONCLUSIONS All the sites monitored showed background noise levels above regulation limits between 7:00 and 21:00. In the intervals between 6:00-6:59 and 21:00-22:59 the noise data, when analyzed with the current airport operational characteristics, still allow the development of additional mitigating measures.

scholarly journals Comparasion of prediction and measurement methods for sound insulation of lightweight partitions

2012 ◽  
Vol 10 (2) ◽  
pp. 155-167 ◽  
Author(s):  
Momir Prascevic ◽  
Dragan Cvetkovic ◽  
Darko Mihajlov
Keyword(s):  
Transmission Loss ◽  
Road Traffic ◽  
Theoretical Models ◽  
Measurement Methods ◽  
Experimental Results ◽  
Sound Insulation ◽  
Acoustic Absorption ◽  
Noise Levels ◽  
Overall Design ◽  
Acoustic Comfort

It is important to know the sound insulation of partitions in order to be able to compare different constructions, calculate acoustic comfort in apartments or noise levels from outdoor sources such as road traffic, and find engineer optimum solutions to noise problems. The use of lightweight partitions as party walls between dwellings has become common because sound insulation requirements can be achieved with low overall surface weights. However, they need greater skill to design and construct, because the overall design is much more complex. It is also more difficult to predict and measure of sound transmission loss of lightweight partitions. There are various methods for predicting and measuring sound insulation of partitions and some of them will be described in this paper. Also, this paper presents a comparison of experimental results of the sound insulation of lightweight partitions with results obtained using different theoretical models for single homogenous panels and double panels with and without acoustic absorption in the cavity between the panels.

scholarly journals Full-Scale Tests for Assessing Blasting-Induced Vibration and Noise

2018 ◽  
Vol 2018 ◽  
pp. 1-14
Author(s):  
Chung-Won Lee ◽  
Jiseong Kim ◽  
Gi-Chun Kang
Keyword(s):  
Noise Level ◽  
Full Scale ◽  
Noise Prediction ◽  
Square Root ◽  
Infrastructure Development ◽  
Full Scale Test ◽  
Noise Levels ◽  
Tunnel Excavation ◽  
Scale Test ◽  
Full Scale Tests

Vibration and noise problems caused by a number of construction processes, specifically blasting for infrastructure development, are becoming important because of their civil appeal. In this study, a square root equation (SRE) with a 95% confidence level was proposed for predicting blasting-induced vibration through full-scale test blasting, and the vibration value predicted from this equation was located between the values predicted from the USBM (US Department of Interior, Bureau of Mines), NOF (Nippon Oil & Fats Co., Ltd.), and MCT (Ministry of Construction and Transportation) equations. Additionally, by comparing the measured noise level at full-scale test blasting with the calculated noise levels from several noise prediction equations, it was determined that the noise level predicted by the ONECRC equation had the best agreement with the measured results. However, in cases where blasting includes tunnel excavation, simultaneous measurement of vibration and noise is required to prevent damage to the surrounding facilities.

scholarly journals Sensitivity Enhancement of NMR Spectroscopy Receiving Chain Used in Condensed Matter Physics

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3064 ◽  
Author(s):  
Petar Kolar ◽  
Mihael S. Grbić ◽  
Silvio Hrabar
Keyword(s):  
Nmr Spectroscopy ◽  
Noise Figure ◽  
Condensed Matter ◽  
A Priori ◽  
Noise Model ◽  
Measurement Time ◽  
Condensed Matter Physics ◽  
Noise Levels ◽  
Proposed Model ◽  
Optimized Conditions

Assurance of high measuring sensitivity is one of the most challenging issues for any nuclear magnetic resonance (NMR) spectroscopy system. To this end, we propose an accurate noise model of the entire probe-to-spectrometer receiving chain for condensed matter physics, based on the concept of noise figure. The model predicts the propagation of both the signal and noise levels in every component of the NMR spectroscopy receiving chain. Furthermore, it enables identification of the "weakest" component and, therefore, the optimization of the whole system. The most important property of the proposed model is the possibility to find system parameters that reduce the measurement time by an a priori calculation, rather than an a posteriori approach. The model was tested experimentally on several different samples. It was found that the measurement time can still be significantly shortened, down to at least one half of the measurement time, starting from optimized conditions with commercially available components. Thus, the proposed model can be used as a tool for both quantitative analysis of the noise properties and a sensitivity prediction of practical NMR systems in physics and material science.

scholarly journals Anisotropic source modelling for turbulent jet noise prediction

2019 ◽  
Vol 377 (2159) ◽  
pp. 20190075 ◽  
Author(s):  
Xihai Xu ◽  
Xiaodong Li
Keyword(s):  
Large Scale ◽  
Noise Source ◽  
Jet Noise ◽  
Source Model ◽  
Noise Prediction ◽  
Reynolds Stresses ◽  
Acoustic Analogy ◽  
Mean Flow ◽  
Navier Stokes Equation ◽  
Anisotropic Source

An anisotropic component of the jet noise source model for the Reynolds-averaged Navier–Stokes equation-based jet noise prediction method is proposed. The modelling is based on Goldstein's generalized acoustic analogy, and both the fine-scale and large-scale turbulent noise sources are considered. To model the anisotropic characteristics of jet noise source, the Reynolds stress tensor is used in place of the turbulent kinetic energy. The Launder–Reece–Rodi model (LRR), combined with Menter's ω -equation for the length scale, with modified coefficients developed by the present authors, is used to calculate the mean flow velocities and Reynolds stresses accurately. Comparison between predicted results and acoustic data has been carried out to verify the accuracy of the new anisotropic source model. This article is part of the theme issue ‘Frontiers of aeroacoustics research: theory, computation and experiment’.

Study on Acoustic Model of Transformer

2014 ◽  
Vol 1008-1009 ◽  
pp. 571-575
Author(s):  
Jing Zhu Hu ◽  
Di Chen Liu ◽  
Qing Fen Liao ◽  
Su Wei ◽  
Lei Yu
Keyword(s):  
Noise Level ◽  
Noise Control ◽  
Noise Source ◽  
Sound Field ◽  
Point Sources ◽  
Equivalent Model ◽  
Noise Prediction ◽  
Acoustic Model ◽  
Plane Source ◽  
Equivalent Source

The model of transformer as a noise source is very critical for substation noise prediction. The transformer is equivalent to several point sources on the basis of regarding the transformer as a combination of several planar sources. This equivalent model is based on equivalent source method and it is convenient and easy. The model of 9 equivalent point sources is simulated to verify that the rebuilt sound field is roughly the same as the actual sound field generated by the plane source. Moreover, the accuracy of the model with different settings was discussed. The acoustic model is accurate and feasible to calculate the noise level radiated by transformer and it is meaningful for substation noise control.

SOUND INSULATION OF A MECHANICAL WORKSHOP

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
ZORAN PETROVIĆ ◽  
BRANKO RADIČEVIĆ ◽  
MILAN KOLAREVIĆ ◽  
VLADAN GRKOVIĆ
Keyword(s):  
Theoretical Model ◽  
Key Words ◽  
Design Process ◽  
Experimental Results ◽  
Sound Insulation ◽  
Housing Estate ◽  
Noise Levels ◽  
Acoustic Insulation

The paper presents a design process related to sound insulation of a small mechanical workshop for storing eccentric presses, which is located in a densely populated housing estate. Starting from the theoretical model of acoustic insulation power of a single solid partition, a complex partition and a multi-layer partition, the acoustic insulation power of the walls and the ceiling in the workshop was determined. The results of calculation of workshop isolation coincide to a great extent with the experimental results of measuring noise levels. Key words: noise, mechanical workshop, sound insulation

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