Combining an energy boundary element analysis with an energy finite element analysis for computing airborne noise inside a flexible structure due to an exterior acoustic source

2006 ◽  
Vol 119 (5) ◽  
pp. 3418-3418
Author(s):  
Geng Zhang ◽  
Nickolas Vlahopoulos
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Boundary Element ◽  
Flexible Structure ◽  
Acoustic Source ◽  
Element Analysis ◽  
Airborne Noise ◽  
Boundary Element Analysis ◽  
Energy Finite Element Analysis

An Investigation of Reverberation Chamber High-Frequency Vibration-Acoustic Problem for an Aircraft Cabin Title

2011 ◽  
Vol 179-180 ◽  
pp. 311-315
Author(s):  
Miao Xia Xie ◽  
Hua Ling Chen ◽  
Jiu Hui Wu ◽  
Xing Liang Zhao
Keyword(s):  
Finite Element Analysis ◽  
Boundary Element ◽  
High Frequency ◽  
Element Analysis ◽  
Reverberation Chamber ◽  
High Frequency Vibration ◽  
Aircraft Cabin ◽  
Acoustic Problem ◽  
Boundary Element Analysis ◽  
Energy Finite Element Analysis

In this paper, reverberation chamber high-frequency vibration-acoustic problem for an aircraft cabin is investigated with two methods. One is combining energy finite element analysis (EFEA) and energy boundary element analysis (EBEA); another is boundary element method by SYSNOISE. Comparison is performed between these two methods.

Applying Incompatible Meshes for Modeling Structural-Acoustic Domains in Energy Finite Element Analysis

2014 ◽  
Author(s):  
S. N. Medyanik ◽  
N. Vlahopoulos
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Differential Equations ◽  
Computationally Efficient ◽  
Exact Matching ◽  
Element Analysis ◽  
Energy Finite Element Analysis ◽  
Accuracy Of Results ◽  
New Formulation ◽  
Acoustic Interface

The Energy Finite Element Analysis (EFEA) has been developed for modeling coupled structural-acoustic systems at mid-to-high frequencies when conventional finite element methods are no longer computationally efficient because they require very fine meshes. In standard Finite Element Analysis (FEA) approach, governing differential equations are formulated in terms of displacements which vary harmonically with space. This requires larger numbers of elements at higher frequencies when wavelengths become smaller. In the EFEA, governing differential equations are formulated in terms of energy density that is spatially averaged over a wavelength and time averaged over a period. The resulting solutions vary exponentially with space which makes them smooth and allows for using much coarser meshes. However, current EFEA formulations require exact matching between the meshes at the boundaries between structural and acoustic domains. This creates practical inconveniences in applying the method as well as limits its use to only fully compatible meshes. In this paper, a new formulation is presented that allows for using incompatible meshes in EFEA modeling, when shapes and/or sizes of elements at structural-acoustic interfaces do not match. In the main EFEA procedure, joints formulations between structural and acoustic domains have been changed in order to deal with non-matching elements. In addition, the new Pre-EFEA procedure which allows for automatic searching and formation of the new types of joints is developed for models with incompatible meshes. The new method is tested using a spherical shaped structural-acoustic interface. Results for incompatible meshes are validated by comparing to solutions obtained using regular compatible meshes. The effects of mesh incompatibility on the accuracy of results are discussed.

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