Parametric Study of the Coupling Power Factor for the Statistical Energy Analysis of Piping Acoustic Vibration

2013 ◽  
Author(s):  
Ahmed H. Dweib
Keyword(s):  
Energy Analysis ◽  
Element Model ◽  
Coupling Factor ◽  
Acoustic Energy ◽  
Piping System ◽  
Statistical Energy Analysis ◽  
Multiple Sources ◽  
Pipe Length ◽  
Flow Equations ◽  
System Parameters

Energy-based finite element model is utilized for the evaluation of the Statistical Energy Analysis (SEA) coupling factor and the dependence of the coupling factor on the different system parameters is studied. Previous research has shown that the coupling factor is largely dependent on the modal densities of the fluid and pipe subsystems, which depend on the pipe dimensional parameters. The coupling factor depends also on the spectrum of the acoustic power generated, which in turn depends on the mass flow rate, the pressure reduction ratio and the characteristics of the pressure-reducing device. This study is concerned with the piping system parameters, downstream of the pressure-reducing valve. The system parameters selected for consideration are the pipe diameter to thickness ratio D/T and the pipe length to diameter ratio L/D. The study presents the effect of the variation in these two dimensionless parameters on the coupling factor. The results of the analysis can be used directly in the formulation of SEA power flow equations for large piping systems with multiple sources of acoustic energy as part of the fatigue life evaluation in critical services.

Sound and Vibration Transmission Through Panels and Tie Beams Using Statistical Energy Analysis

1971 ◽  
Vol 93 (3) ◽  
pp. 775-781 ◽  
Author(s):  
M. J. Crocker ◽  
M. C. Battacharya ◽  
A. J. Price
Keyword(s):  
Energy Analysis ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Accurate Method ◽  
Acoustic Energy ◽  
Statistical Energy Analysis ◽  
Sound Transmission Loss ◽  
Lateral Shear ◽  
Architectural Acoustics ◽  
Bending Waves

The transmission of sound and vibration through structures is of interest in many noise control problems, including architectural acoustics, sound transmission through aircraft, spacecraft and ships, and the transmission of noise through machinery and engine enclosures. Statistical energy analysis provides a simple and accurate method of approaching these problems. In this paper, theory is examined for the transmission of acoustic energy through single panels, independent double panels, and double panels connected with tie beams. In the single panel case, the theoretical model consists of three linearly coupled oscillators; room-panel-room. The independent double panel case consists of five oscillators; room-panel-cavity-panel-room. In the connected double panel case, the tie beams must be accounted for as the sixth oscillator. A coupling loss factor is determined for the ties by considering the transmission of longitudinal waves, bending waves, and lateral shear waves in the ties. Both resonant and nonresonant transmission are included in the theory. It is shown that for a single panel, the experimental sound transmission loss, panel radiation resistance, and vibration amplitude are all well predicted by the theory. The experimental sound transmission loss is also well predicted in the independent double panel and coupled double panel cases.

On a structural–acoustic panel cavity modelling in the mid-high frequency domain

2011 ◽  
Vol 226 (4) ◽  
pp. 900-912 ◽  
Author(s):  
M de Rochambeau ◽  
M Ichchou ◽  
B Troclet
Keyword(s):  
Finite Element ◽  
Frequency Domain ◽  
High Frequency ◽  
Energy Analysis ◽  
Coupled System ◽  
Element Model ◽  
Statistical Energy Analysis ◽  
Hybrid Strategy ◽  
Interaction Modelling

This article presents a fluid–structure interaction modelling, based on a coupling between component mode synthesis or finite element and statistical energy analysis (SEA). The hybrid strategy is applied on a panel–cavity coupled system using a modal analysis with uncoupled modes of the subsystems and through a finite element model of the coupled system. The determination of the energy transfer parameters is then considered. The hybrid SEA model is then validated in the high-frequency domain by comparison with an SEA model. Finally, a parametric survey is offered through the established modelling and conclusions on its validity domain are drawn.

Statistical Energy Analysis for Electronic Equipment

1991 ◽  
Vol 113 (3) ◽  
pp. 322-325
Author(s):  
L. Lu
Keyword(s):  
Mathematical Model ◽  
High Frequency ◽  
Vibration Analysis ◽  
Energy Analysis ◽  
Element Model ◽  
Electronic Equipment ◽  
System Response ◽  
Statistical Energy Analysis ◽  
Simple Mathematical Model ◽  
Good Agreement

Vibration response of electronic equipment analyzed by a simple mathematical model or a finite element model can only provide a limited system response calculation. Application of the Statistical Energy Analysis (SEA) was extended to the calculation of the vibrations of individual components. In order to demonstrate the applicability of SEA to instrumentation vibration analysis at high frequency ranges, an 8-component electronic box was chosen for test and analysis. There was good agreement between tested and analytical results in the frequency averaged sense.

Statistical Energy Analysis of Fluid-Filled Piping Vibrations and Acoustics

2002 ◽  
Author(s):  
Jerome E. Manning
Keyword(s):  
Acoustic Waves ◽  
Energy Analysis ◽  
Prediction Models ◽  
Piping System ◽  
Statistical Energy Analysis ◽  
Coupled Vibration ◽  
Noise Emission ◽  
Structural Vibrations ◽  
Piping Systems ◽  
Acoustic Space

The flow of vibratory energy in turbo-machinery piping systems can contribute significantly to the noise emission. Fluctuating pressures and mechanical vibrations of pumps and valves generate coupled vibration and acoustic waves that propagate throughout the system and radiate noise to the surrounding acoustic space. Statistical energy analysis provides a method to analyze the energy transmitted by these waves and to develop noise and vibration mitigation designs. The development of SEA models requires that special consideration be given to piping elbows and tees, where the coupling between structural vibrations and fluid acoustic waves may be high. This paper reviews the development of piping system prediction models and their limitations. A mobility-based approach is described to improve predictions at mid-frequencies where both statistical energy and finite element procedures often fail to provide accurate predictions.

The Feasibility of Statistical Energy Analysis in the Modeling of Stringed Musical Instruments

2010 ◽  
Author(s):  
Hossein Mansour
Keyword(s):  
Finite Element ◽  
Structural Modification ◽  
Energy Analysis ◽  
Element Model ◽  
Musical Instruments ◽  
Statistical Energy Analysis ◽  
Reliable Model ◽  
Challenging Tasks ◽  
High Degree ◽  
Vibrating Systems

Stringed musical instruments are complex vibrating systems both from structural and fluid-structure coupling perspectives; hence, their modeling is one of the most challenging tasks in the area of vibration and acoustics. Making a reliable model not only broadens our knowledge of the physics of these instruments, but also it simplifies the procedure of structural modification and optimization on them. In this regard, a Finite Element Model has been previously made from Setar and is verified with the experimental results. Although that model could precisely simulate the instrument in lower frequencies (i.e. below 2.5 KHz), its results showed a weak correlation with reality in higher frequencies. In fact, unreliable results and high computational demand are common drawbacks of finite element method in higher frequencies. To avoid these problems, in this study Setar is modeled with Statistical Energy Analysis (SEA) approach. This method is more efficient in dealing with high degree of uncertainty in the system. SEA does this by averaging the response over the frequency and location to gain a more general and reliable result. Application of SEA in higher frequencies is, in fact, compatible with the nature of musical instruments where in higher frequencies we are mostly interested in the trend of the response rather than the location of each individual peak.

Experimental and Statistical Energy Analysis of the Structure-borne Noise in a Helicopter Cabin

2017 ◽  
Vol 10 (6) ◽  
pp. 323
Author(s):  
Raffaella Di Sante ◽  
Marcello Vanali ◽  
Elisabetta Manconi ◽  
Alessandro Perazzolo
Keyword(s):  
Energy Analysis ◽  
Statistical Energy Analysis

Power Flow and Energy Sharing between an Oscillator and a Continuous Receiver Structure

2011 ◽  
Vol 189-193 ◽  
pp. 1914-1917
Author(s):  
Lin Ji
Keyword(s):  
High Frequency ◽  
Power Flow ◽  
Energy Analysis ◽  
Statistical Energy Analysis ◽  
Coupled Subsystems ◽  
Modal Density ◽  
Vibration Problems ◽  
Energy Sharing ◽  
High Modal Density ◽  
Vibration Modeling

A key assumption of conventional Statistical Energy Analysis (SEA) theory is that, for two coupled subsystems, the transmitted power from one to another is proportional to the energy differences between the mode pairs of the two subsystems. Previous research has shown that such an assumption remains valid if each individual subsystem is of high modal density. This thus limits the successful applications of SEA theory mostly to the regime of high frequency vibration modeling. This paper argues that, under certain coupling conditions, conventional SEA can be extended to solve the mid-frequency vibration problems where systems may consist of both mode-dense and mode-spare subsystems, e.g. ribbed-plates.

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