An Efficient Frequency-Domain Algorithm for Wave Scattering Problems in Application to Jet Noise

2005 ◽  
Author(s):  
Sergey Karabasov ◽  
Tom Hynes
Keyword(s):  
Frequency Domain ◽  
Wave Scattering ◽  
Jet Noise ◽  
Scattering Problems

Parallel Volume Integral Equation Method for Two-Dimensional Elastodynamic Analysis

2019 ◽  
Vol 16 (06) ◽  
pp. 1840025
Author(s):  
Jungki Lee ◽  
Hogwan Jeong
Keyword(s):  
Integral Equation ◽  
Wave Scattering ◽  
Integral Equation Method ◽  
Equation Method ◽  
Two Dimensional ◽  
Volume Integral ◽  
Scattering Problems ◽  
Volume Integral Equation ◽  
Parallel Volume ◽  
Volume Integral Equation Method

The parallel volume integral equation method (PVIEM) is applied for the analysis of two-dimensional elastic wave scattering problems in an unbounded isotropic solid containing various types of multiple multilayered anisotropic inclusions. It should be noted that the volume integral equation method (VIEM) does not require the use of the Green’s function for the anisotropic inclusion — only the Green’s function for the unbounded isotropic matrix is needed. A detailed analysis of the SH wave scattering problem is presented for various types of multiple multilayered orthotropic inclusions. Numerical results are presented for the elastic fields at the interfaces for square and hexagonal packing arrays of various types of multilayered orthotropic inclusions in a broad frequency range of practical interest. Standard parallel programming was used to speed up computation in the VIEM. The PVIEM enables us to investigate the effects of single/multiple scattering, fiber packing type, fiber volume fraction, single/multiple layer(s), multilayer’s shapes and geometry, isotropy/anisotropy, and softness/hardness of various types of multiple multilayered anisotropic inclusions on displacements and stresses at the interfaces of the inclusions and far-field scattering patterns. Also, powerful capabilities of the PVIEM for the analysis of general two-dimensional multiple scattering problems are investigated.

Wave Problems for Repetitive Structures and Symplectic Mathematics

1992 ◽  
Vol 206 (6) ◽  
pp. 371-379 ◽  
Author(s):  
W X Zhong ◽  
F W Williams
Keyword(s):  
Wave Scattering ◽  
Power Flow ◽  
Turbine Blades ◽  
Expansion Method ◽  
Space Structures ◽  
Scattering Problems ◽  
Symplectic Matrix ◽  
Conservation Result ◽  
Wave Problems ◽  
Chain Type

Based on the analogy between structural mechanics and optimal control theory, the eigensolutions of a symplectic matrix, the adjoint symplectic ortho-normalization relation and the eigenvector expansion method are introduced into the wave propagation theory for sub-structural chain-type structures, such as space structures, composite material and turbine blades. The positive and reverse algebraic Riccati equations are derived, for which the solution matrices are closely related to the power flow along the sub-structural chain. The power flow orthogonality relation for various eigenvectors is proved, and the energy conservation result is also proved for wave scattering problems.

WATER WAVE SCATTERING BY A VERTICAL POROUS BARRIER WITH TWO GAPS

2019 ◽  
Vol 61 (1) ◽  
pp. 47-63 ◽  
Author(s):  
M. SIVANESAN ◽  
S. R. MANAM
Keyword(s):  
Water Wave ◽  
Wave Scattering ◽  
Original Problem ◽  
Analytical Procedure ◽  
Explicit Solutions ◽  
Scattering Problems ◽  
Geometrical Structures ◽  
Water Wave Scattering ◽  
Weakly Singular ◽  
Porous Barrier

Explicit solutions are rarely available for water wave scattering problems. An analytical procedure is presented here to solve the boundary value problem associated with wave scattering by a complete vertical porous barrier with two gaps in it. The original problem is decomposed into four problems involving vertical solid barriers. The decomposed problems are solved analytically by using a weakly singular integral equation. Explicit expressions are obtained for the scattering amplitudes and numerical results are presented. The results obtained can be used as a benchmark for other wave scattering problems involving complex geometrical structures.

scholarly journals On Accuracy of Analytical Modeling of Lamb Wave Scattering at Delaminations in Multilayered Isotropic Plates

2015 ◽  
Vol 15 (08) ◽  
pp. 1540010 ◽  
Author(s):  
C. T. Ng
Keyword(s):  
Analytical Solutions ◽  
Lamb Wave ◽  
Wave Scattering ◽  
Plate Theory ◽  
Analytical Models ◽  
Mindlin Plate ◽  
Bending Rigidity ◽  
Scattering Problems ◽  
Explicit Finite Element ◽  
Isotropic Plates

The study investigates the accuracy of analytical solutions to the fundamental anti-symmetric Lamb wave scattering at delamination in multilayered isotropic plates. The analytical models are based on the wave function expansion method and Born approximation within the framework of Mindlin plate theory. The study validates the accuracy of modeling the delamination as an inhomogeneity with reduced bending rigidity in predicting Lamb wave scattering induced by geometry change at the delaminated region. A good agreement is observed between the analytical solutions and results of experimentally verified 3D explicit finite element (FE) simulations. The findings support the inhomogeneity assumption in Lamb wave scattering problems and show the feasibility of employing it in delamination characterization.

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