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.

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.

scholarly journals High Frequency Analysis of a Point-Coupled Parallel Plate System

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Dean R. Culver ◽  
Earl H. Dowell
Keyword(s):  
Modal Analysis ◽  
High Frequency ◽  
Parallel Plate ◽  
Energy Analysis ◽  
Spatial Relationship ◽  
Statistical Energy Analysis ◽  
Mean Square ◽  
Parallel Plates ◽  
Modal Density ◽  
Plate System

The root-mean-square (RMS) response of various points in a system comprised of two parallel plates coupled at a point undergoing high frequency, broadband transverse point excitation of one component is considered. Through this prototypical example, asymptotic modal analysis (AMA) is extended to two coupled continuous dynamical systems. It is shown that different points on the plates respond with different RMS magnitudes depending on their spatial relationship to the excitation or coupling points in the system. The ability of AMA to accurately compute the RMS response of these points (namely, the excitation point, the coupling points, and the hot lines through the excitation or coupling points) in the system is shown. The behavior of three representative prototypical configurations of the parallel plate system considered is: two similar plates (in both geometry and modal density), two plates with similar modal density but different geometry, and two plates with similar geometry but different modal density. After examining the error between reduced modal methods (such as AMA) to classical modal analysis (CMA), it is determined that these several methods are valid for each of these scenarios. The data from the various methods will also be useful in evaluating the accuracy of other methods including statistical energy analysis (SEA).

Asymptotic Modal Analysis and Statistical Energy Analysis of Dynamical Systems

1985 ◽  
Vol 52 (4) ◽  
pp. 949-957 ◽  
Author(s):  
E. H. Dowell ◽  
Y. Kubota
Keyword(s):  
Asymptotic Behavior ◽  
Dynamical Systems ◽  
Modal Analysis ◽  
Energy Analysis ◽  
Asymptotic Limit ◽  
General Linear ◽  
Statistical Energy Analysis ◽  
Structural System ◽  
Numerical Example ◽  
Almost All

A new derivation of the results commonly referred to as Statistical Energy Analysis (SEA) is given by studying the asymptotic behavior of classical modal analysis for a general, linear (structural) system. It is shown that, asymptotically, the response at (almost) all points of the system is the same. A numerical example is used to illustrate the way in which the asymptotic limit is approached. Both random and sinusoidal loadings are considered; for the latter an extension of the usual SEA result is obtained.

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.

scholarly journals Ergodic billiard and statistical energy analysis

Wave Motion ◽  
2019 ◽  
Vol 87 ◽  
pp. 166-178 ◽  
Author(s):  
H. Li ◽  
N. Totaro ◽  
L. Maxit ◽  
A. Le Bot
Keyword(s):  
Energy Analysis ◽  
Statistical Energy Analysis
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