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.

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.

The Effect of Direct Field Component on a Statistical Energy Analysis (SEA) Model

2013 ◽  
Vol 471 ◽  
pp. 279-284 ◽  
Author(s):  
Azma Putra ◽  
Al Munawir ◽  
W.M.F.W. Mohamad ◽  
J.I. Mohammad
Keyword(s):  
Field Component ◽  
Energy Analysis ◽  
Complex Structure ◽  
Sound Field ◽  
Injection Technique ◽  
Statistical Energy Analysis ◽  
Coupling Loss ◽  
Model Assumption ◽  
Power Injection ◽  
Acoustic Space

Statistical Energy Analysis (SEA) is a well-known method to analyze the flow of acoustic and vibration energy in a complex structure. The structure is divided into subsystems where the energy in each of the subsystem is assumed to be reverberant. This study investigates the application of SEA model in a 'damped' acoustic space where the direct field component from the sound source dominates the total sound field rather than a diffuse field in a reverberant space which the SEA model assumption is based on. A measurement was conducted in a scaled room divided into two acoustic spaces separated by a partition with an opening. Absorbent materials were installed on the room walls and the power injection technique was implemented to obtain the coupling loss factor (CLF) of the system. It is found that correction of the direct field component from the subsystem energy improves the prediction of the CLF of the system.

scholarly journals Corrected Statistical Energy Analysis Model in a Non-Reverberant Acoustic Space

2021 ◽  
Vol 55 (3) ◽  
pp. 203-219
Author(s):  
Al Munawir ◽  
Azma Putra ◽  
Iwan Prasetiyo ◽  
Wan Mohd Farid Wan Mohamad ◽  
Safarudin Herawan
Keyword(s):  
Energy Analysis ◽  
Statistical Energy Analysis ◽  
Analysis Model ◽  
Acoustic Space

Asymptotic Modal Analysis and Statistical Energy Analysis of an Acoustic Cavity

1988 ◽  
Vol 110 (3) ◽  
pp. 371-376 ◽  
Author(s):  
Y. Kubota ◽  
H. D. Dionne ◽  
E. H. Dowell
Keyword(s):  
Modal Analysis ◽  
Wall Motion ◽  
Energy Analysis ◽  
Theoretical Work ◽  
Statistical Energy Analysis ◽  
Structural Vibrations ◽  
Structural Wall ◽  
Acoustic Cavity ◽  
Substantial Progress ◽  
Made In

One of the outstanding theoretical questions in interior noise is the connection between modal analysis and statistical energy analysis. Recently substantial progress has been made in understanding this connection for structural vibrations including both fundamental theoretical work and experimental verification. It has been shown that many of the results of Statistical Energy Analysis can be derived as an asymptotic limit of classical modal analysis and thus this approach is called Asymptotic Modal Analysis. The basic asymptotic theory for structural wall-acoustic cavity interaction is described in this paper. Several numerical examples are presented for acoustic cavity response with a prescribed wall motion to illustrate the key results of the theory.

Applying constrained layer damping to reduce vibration and noise from a steel-concrete composite bridge: An experimental and numerical investigation

2018 ◽  
Vol 22 (6) ◽  
pp. 1743-1769 ◽  
Author(s):  
Quanmin Liu ◽  
Xiaozhen Li ◽  
Xun Zhang ◽  
Yunlai Zhou ◽  
Y Frank Chen
Keyword(s):  
Strain Energy ◽  
Energy Analysis ◽  
Constrained Layer Damping ◽  
Statistical Energy Analysis ◽  
Train Track ◽  
Coupled Vibration ◽  
Modal Strain Energy ◽  
Composite Bridge ◽  
Track Bridge ◽  
Loss Factors

Structure-borne noise from railway bridges has become increasingly severe due to increased train speeds and axle loads. Constrained layer damping can suppress structural vibration and noise considerably across a wide frequency range by dissipating vibrational energy via damping layer shear deformation. This paper proposes a theoretical method of calculating the train-induced vibration and noise of a constrained layer damping-enhanced railway bridge based on the train–track–bridge coupled vibration, the modal strain energy method, and statistical energy analysis. First, the vibration responses of bridge decks were obtained via train–track–bridge coupled vibration calculations. Second, the constrained layer damping subsystem modal loss factors were determined via modal strain energy analysis and converted to damping loss factors in 1/3 octave band. Third, upon substituting the vibration energies of the decks and the damping loss factors of constrained layer damping subsystems into the statistical energy analysis power balance equations, the transmitted vibration energy results from various bridge subsystems were determined by solving the referenced equations. The structure-borne noise from the bridge was finally determined by analyzing the vibratory energies of all of the bridge subsystems using vibro-acoustic theory. Numerical analysis and field measurements of vibration and noise from a three-span steel–concrete composite bridge before and after constrained layer damping installation were performed. The predicted train-induced vibration and noise agreed well with the measured results. The stringer web and flange vibration velocity levels were reduced by 10.5 dB and 6.1 dB, respectively, and the sound pressure level at a measurement point 25 m (horizontal) from the track centerline and 1.5 m off the ground decreased by 4.3 dB(A).

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

Non-Linear Design Verification of Nuclear Power Piping According to ASME III NB/NC

2008 ◽  
Author(s):  
Lingfu Zeng ◽  
Lennart G. Jansson
Keyword(s):  
Nuclear Power ◽  
Design Evaluation ◽  
Piping System ◽  
Design Verification ◽  
Intensive Study ◽  
Non Linear ◽  
Piping Systems ◽  
Design Requirements

A nuclear piping system which is found to be disqualified, i.e. overstressed, in design evaluation in accordance with ASME III, can still be qualified if further non-linear design requirements can be satisfied in refined non-linear analyses in which material plasticity and other non-linear conditions are taken into account. This paper attempts first to categorize the design verification according to ASME III into the linear design and non-linear design verifications. Thereafter, the corresponding design requirements, in particular, those non-linear design requirements, are reviewed and examined in detail. The emphasis is placed on our view on several formulations and design requirements in ASME III when applied to nuclear power piping systems that are currently under intensive study in Sweden.

Comparison of Failure Modes of Piping Systems With Wall Thinning Subjected to In-Plane, Out-of-Plane, and Mixed Mode Bending Under Seismic Load: An Experimental Approach

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Izumi Nakamura ◽  
Akihito Otani ◽  
Masaki Shiratori
Keyword(s):  
Dynamic Behavior ◽  
Failure Modes ◽  
Seismic Load ◽  
Piping System ◽  
Shake Table ◽  
Shake Table Tests ◽  
Wall Thinning ◽  
Piping Systems ◽  
Out Of Plane ◽  
Plane Bending

Pressurized piping systems used for an extended period may develop degradations such as wall thinning or cracks due to aging. It is important to estimate the effects of degradation on the dynamic behavior and to ascertain the failure modes and remaining strength of the piping systems with degradation through experiments and analyses to ensure the seismic safety of degraded piping systems under destructive seismic events. In order to investigate the influence of degradation on the dynamic behavior and failure modes of piping systems with local wall thinning, shake table tests using 3D piping system models were conducted. About 50% full circumferential wall thinning at elbows was considered in the test. Three types of models were used in the shake table tests. The difference of the models was the applied bending direction to the thinned-wall elbow. The bending direction considered in the tests was either of the in-plane bending, out-of-plane bending, or mixed bending of the in-plane and out-of-plane. These models were excited under the same input acceleration until failure occurred. Through these tests, the vibration characteristic and failure modes of the piping models with wall thinning under seismic load were obtained. The test results showed that the out-of-plane bending is not significant for a sound elbow, but should be considered for a thinned-wall elbow, because the life of the piping models with wall thinning subjected to out-of-plane bending may reduce significantly.

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