Comparison of Statistical Energy Analysis power flow predictions with an ’’exact’’ calculation

1975 ◽  
Vol 57 (2) ◽  
pp. 374-379 ◽  
Author(s):  
Paul J. Remington ◽  
Jerome E. Manning
Keyword(s):  
Power Flow ◽  
Energy Analysis ◽  
Exact Calculation ◽  
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.

Mechanical Power Flow Between Stiffened Plates and Viscoelastic Discrete Systems

1986 ◽  
Vol 108 (2) ◽  
pp. 155-164 ◽  
Author(s):  
E. Goldfracht ◽  
G. Rosenhouse
Keyword(s):  
Power Flow ◽  
Energy Analysis ◽  
Power Transmission ◽  
Discrete Systems ◽  
Vibration Energy ◽  
Stiffened Plates ◽  
Statistical Energy Analysis ◽  
Frequency Range ◽  
Lower Frequency Range ◽  
Fundamental Theorems

In this paper we primarily discuss a theory of power transmission and vibration energy distribution of dynamically loaded structures. The loads are random and the system comprises linked elements, which consist of machine-supported stiffened plates. Fundamentally, the theory is deterministic, but in addition it uses some features of the SEA. In fact, the analysis is intended to verify fundamental theorems of the Statistical Energy Analysis in the lower frequency range.

Statistical Energy Analysis for the Time-Integrated Transient Response of Vibrating Systems

1990 ◽  
Vol 112 (2) ◽  
pp. 206-213 ◽  
Author(s):  
M. L. Lai ◽  
A. Soom
Keyword(s):  
Steady State ◽  
Energy Balance ◽  
Transient Response ◽  
Power Flow ◽  
Energy Analysis ◽  
Statistical Energy Analysis ◽  
Balance Equations ◽  
Integrated Response ◽  
Energy Relations ◽  
Loss Factors

For more than twenty years, statistical energy analysis (SEA) has been used for the analysis of steady-state response distributions in complex coupled structures and sound-structure systems. However, the steady-state SEA formalism is not directly applicable to the analysis of transient vibrations. In this paper, energy relations, analogous to steady-state SEA power flow relations, are derived for the time-integrated transient response of each oscillator. These energy flow relations can be combined using statistical concepts, to obtain a set of energy balance equations for N coupled multimodal subsystems. It is shown that the time-integrated response of each subsystem can be described in terms of transient input energies and conventional SEA parameters, i.e., modal densities, loss factors and coupling loss factors. By solving the energy balance equations, the time-integrated response of each subsystem can be obtained. The results of experiments, conducted on a coupled structure consisting of two welded plates, are presented to illustrate the applicability of these relations.

Prediction of insertion loss of lagging in rectangular duct using statistical energy analysis

2019 ◽  
Vol 67 (6) ◽  
pp. 438-446
Author(s):  
M. Yoganandh ◽  
Jade Nagaraja ◽  
B. Venkatesham
Keyword(s):  
Insertion Loss ◽  
Power Flow ◽  
Energy Analysis ◽  
Transmission Loss ◽  
Flow Analysis ◽  
Computational Cost ◽  
Statistical Energy Analysis ◽  
Rectangular Duct ◽  
Modal Density ◽  
Element Method

In this article, statistical energy analysis (SEA) is used to predict insertion loss from a lagged rectangular HVAC duct. For a lagged duct, all duct walls are treated from outside with acoustic material. Although deterministic methods like the finite element method (FEM), boundary element method (BEM), and wave based methods can predict the breakout noise, these methods have limitations in handling systems with high modal density due to higher computational cost. In this study, a rectangular duct is divided into six subsystems, which are four duct walls (each wall considered as a subsystem), internal air cavity and external airspace. Power flow analysis is performed on all subsystems to calculate transverse transmission loss of an unlined duct and insertion loss for a lagged duct. Predicted transverse transmission loss values are validated with ASHRAE data and Insertion loss values with literature. The results obtained are in good agreement.

scholarly journals Entropy and Mixing Entropy for Weakly Nonlinear Mechanical Vibrating Systems

Entropy ◽  
2019 ◽  
Vol 21 (5) ◽  
pp. 536 ◽  
Author(s):  
Zahra Sotoudeh
Keyword(s):  
Nonlinear Systems ◽  
Linear Systems ◽  
Power Flow ◽  
Energy Analysis ◽  
Vibrational Temperature ◽  
Statistical Energy Analysis ◽  
Phase Volume ◽  
Weakly Nonlinear ◽  
Mixing Entropy ◽  
Energy Behavior

In this paper, we examine Khinchin’s entropy for two weakly nonlinear systems of oscillators. We study a system of coupled Duffing oscillators and a set of Henon–Heiles oscillators. It is shown that the general method of deriving the Khinchin’s entropy for linear systems can be modified to account for weak nonlinearities. Nonlinearities are modeled as nonlinear springs. To calculate the Khinchin’s entropy, one needs to obtain an analytical expression of the system’s phase volume. We use a perturbation method to do so, and verify the results against the numerical calculation of the phase volume. It is shown that such an approach is valid for weakly nonlinear systems. In an extension of the author’s previous work for linear systems, a mixing entropy is defined for these two oscillators. The mixing entropy is the result of the generation of entropy when two systems are combined to create a complex system. It is illustrated that mixing entropy is always non-negative. The mixing entropy provides insight into the energy behavior of each system. The limitation of statistical energy analysis motivates this study. Using the thermodynamic relationship of temperature and entropy, and Khinchin’s entropy, one can define a vibrational temperature. Vibrational temperature can be used to derive the power flow proportionality, which is the backbone of the statistical energy analysis. Although this paper is motivated by statistical energy analysis application, it is not devoted to the statistical energy analysis of nonlinear systems.

Statistical Energy Analysis of Wind Noise in High-Speed Train Cab

2012 ◽  
Vol 249-250 ◽  
pp. 307-313 ◽  
Author(s):  
Xiao Yan Yang ◽  
You Gang Xiao ◽  
Yu Shi
Keyword(s):  
High Speed ◽  
Power Flow ◽  
Energy Analysis ◽  
Simulation Method ◽  
Statistical Energy Analysis ◽  
High Speed Train ◽  
Wind Noise ◽  
Modal Density ◽  
Head Surface ◽  
Loss Factors

Statistical energy analysis(SEA) method has many advantages in analysis of high frequency, high modal density and complex dynamic systems. Dividing high-speed train cab into a series of sub-systems, the SEA model of high-speed train cab was established. The factors affecting the cab noise, such as modal density, damping loss factors, coupling loss factors, were gotten by theoretical analysis combined with experiments. Using large eddy simulation method, the fluctuation pressures from train head surface were calculated. Using fluctuation pressure as excitation source, wind noise spectra and power flow of sub-systems in cab were obtained, which provided the basis for the control of high-speed train cab noise.

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
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