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Showing 1 to 20 of 24 for “"Perfectly matched layer"”.
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A Perfectly Matched Layer Method for the Navier-Stokes equations
The Perfectly Matched Layer Method (PML) has found widespread application as a high-accuracy, non-reflecting boundary treatment in many wave propagation simulations. However, in the area of computational fluid dynamics, its application has been mostly limited to the linearized Euler equations. …
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An investigation of the perfectly matched layer for inhomogeneous media
Although perfectly matched layers (PMLs) have been widely used to truncate numerical simulations of electromagnetism and other wave equations, we point out important cases in which a PML fails to be reflectionless even in the limit of infinite resolution. In particular, the underlying …
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Perfectly Matched Layer Absorbing Boundary Conditions for the Discrete Velocity Boltzmann-BGK Equation
<p>Perfectly Matched Layer (PML) absorbing boundary conditions were first proposed by Berenger in 1994 for the Maxwell's equations of electromagnetics. Since Hu first applied the method to Euler's equations in 1996, progress made in the application of PML to Computational Aeroacoustics (CAA) …
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Analysis and Application of Perfectly Matched Layer Absorbing Boundary Conditions for Computational Aeroacoustics
<p>The Perfectly Matched Layer (PML) was originally proposed by Berenger as an absorbing boundary condition for Maxwell's equations in 1994 and is still used extensively in the field of electromagnetics. The idea was extended to Computational Aeroacoustics in 1996, when Hu applied the method to …
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A Higher-Order Perfectly Matched Layer for Open-Region, Waveguide, and Periodic Electromagnetic Problems
In this dissertation the idea of a higher-order perfectly matched layer (PML) is proposed. Using a metric coefficient that includes both the regular and the complex frequency shifted (CFS) PMLs, it is possible to obtain a PML that includes the advantages of both of them. The second-order PML is …
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Optimal Spatial Grids for Efficient Numerical Simulation of Time-Domain Electromagnetic Phenomena by Finite Methods
… a novel application of optimal grids to perfectly matched layer absorbing boundary conditions is presented. In this development, a single optimal grid combining the interior computational and exterior absorbing regions (with Dirichlet or Neumann boundary) is constructed, and the perfectly …
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Effects of tool positions on borehole acoustic measurements : a stretched grid finite difference approach
… difference operator and anisotropic perfectly matched layer. This algorithm reduces numerical reflections and wave distortions introduced by grid change to a minimum by sampling the physical space with gradually varying mesh. By coordinate stretching, the algorithm discretizes the …
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A Streamline Upwind/ Petrov-Galerkin FEM based time-accurate solution of 3D time-domain Maxwell's equations for dispersive materials
… patterns and radar cross sections. A unified perfectly matched layer absorbing boundary layer is implemented to efficiently terminate the computational region. Numerical simulations of these equations are tightly coupled together and compared against a loosely coupled approach to improve …
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2-D Modeling of Electromagnetic Waves with Vibrating Conducting and Dielectric Objects
… near-to-far-field transformation, convolutional perfectly matched layer boundary conditions and an advanced surface boundary condition that accommodates the surface perturbations of the vibrating objects. Reflection and diffraction of incident plane waves are calculated for stationary and …
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Efficient mesh truncation techniques for the solution of Maxwell's equations using the finite-difference time domain method
… to simulate the infinite domain. The Berenger perfectly matched layer (PML) technique is shown to offer the potential for near reflectionless absorption of propagating waves at the expense of additional layers of absorbing material with twice the number of unknowns as in the interior domain. …
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Design and simulation for the fabrication of integrated semiconductor optical logic gates
… complex-frequency leaky mode computations with perfectly matched layer (PML) boundary conditions. Finite difference time domain (FDTD) method with PML is utilized in calculating reflections produced by abrupt interfaces, including a tip of an adiabatic taper coupler.
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Advanced Time-Domain Finite-Element Method for Electromagnetic Analysis
… both two-dimensional and three-dimensional perfectly matched layer (PML) schemes are developed for TDFEM simulation of open-region electromagnetic scattering and radiation problems. Sixth, a general approach is proposed for the stability analysis of the TDFEM. Finally, the great application …
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A Higher-Order Finite Element Method for Computing the Radar Cross Section of Bodies of Revolution
… using two methods. The first method is the perfectly matched layer (PML). This method has a number of parameters that must be optimized to obtain good results. Furthermore, the PML must be kept a reasonable distance away from the scatterer, which causes the number of unknowns to be …
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Propagation Of Sound In The Vicinity Of Rigid Porous Interfaces
… are considered: (1) a semi-infinite porous layer; (2) a porous hard-backed surface; and (3) a porous impedance-backed layer. A closed-form solution and numerical methods are derived with respect to each rigid porous interface condition.</p> <p>A modified saddle-point method is exploited to …
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Effective development of cylindrical finite-difference time-domain for electromagnetics applications
… and collect the results. Thus, a conventional perfectly matched layer (PML) can be used to truncate computational regions in numerical methods. This will reduce the memory size and the time to complete the run. However, the accuracy of the PML is necessary in finite-difference time-domain …
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Modelling and analysis of complex electromagnetic problems using FDTD subgridding in hybrid computational methods. Development of hybridised Method of Moments, Finite-Difference Time-Domain method and subgridded Finite-Difference Time-Domain method for precise computation of electromagnetic interaction with arbitrarily complex geometries
… geometries are modelled. However, the Perfectly Matched Layer (PML) concept has been employed to circumvent this difficulty. The establishment of edge elements has greatly improved the performance of this method and the computational burden due to huge numbers of time steps, in the …
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Finite element modelling of photonic crystal fibres
… (BPM) based on the versatile FEM. The robust perfectly matched layer (PML) boundary condition has been introduced to the modal solution approach. The effects of d2/A, operating wavelength and number of air holes have been thoroughly detailed and explained. In this study, it has been identified …
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Finite element characterisation of photonic crystal fibres
… of the conformal transformation and the Perfectly Matched Layer (PML) were undertaken to determine the bending and leakage losses of several designs of Photonic Crystal Fibres. This was carried out by varying key parameters such as the pitch (Λ), diameter (d) and air-filling fraction …
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Detection and assessment of wood decay – glulam beams and wooden utility poles
… directly from CT scans of the utility poles, a perfectly matched layer used to model the behavior or rot, and a center point formulation that allows waves to pass through the center of a cylindrically orthotropic medium. The simulation is validated against the waveform behavior predicted by an …
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