Computation of Local Differential Parameters on Irregular Meshes

2000 ◽  
pp. 19-33 ◽  
Author(s):  
Péter Csákány ◽  
Andrew M. Wallace
Keyword(s):  
Irregular Meshes

Prospective Digital Processing Methods of Multidimensional Signals with the Use of Irregular Meshes

Vestnik MEI ◽  
2019 ◽  
Vol 3 (3) ◽  
pp. 98-107
Author(s):  
Sergey V. Vishnyakov ◽  
◽  
Elizaveta A. Sokolova ◽  
Vitaliy V. Pekhterev ◽  
◽  
...  
Keyword(s):  
Digital Processing ◽  
Processing Methods ◽  
Multidimensional Signals ◽  
Irregular Meshes

Lattice Boltzmann method on irregular meshes

1998 ◽  
Vol 58 (4) ◽  
pp. R4124-R4127 ◽  
Author(s):  
Gongwen Peng ◽  
Haowen Xi ◽  
Comer Duncan ◽  
So-Hsiang Chou
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Irregular Meshes ◽  
Boltzmann Method

scholarly journals Marker Re-Distancing (MRD) Algorithm for High-Fidelity Interface Tracking on Arbitrary Meshes

2017 ◽  
Author(s):  
Patrick T. Greene ◽  
Robert Nourgaliev ◽  
Samuel P. Schofield
Keyword(s):  
Material Flow ◽  
High Order ◽  
Interface Tracking ◽  
High Fidelity ◽  
Time Step ◽  
Tracking Method ◽  
Flow Problems ◽  
Constrained Minimization Problem ◽  
Irregular Meshes ◽  
Stability Time

A new sharp high-order interface tracking method for multi-material flow problems on unstructured meshes is presented. This marker re-distancing (MRD) method is designed to work accurately and robustly on unstructured, generally highly distorted meshes, necessitated by applications within ALE-based hydrocodes. The method is a hybrid of a Lagrangian marker tracking method and a novel discontinuous Galerkin (DG) projection based level set re-distancing algorithm. The re-distancing method is formulated as a constrained minimization problem and is shown to obtain arbitrary orders of convergence for smooth interfaces. High-order (>2nd) re-distancing on irregular meshes is a must for applications were the interfacial curvature is important for the underlying physics, such as surface tension, wetting, and detonation shock dynamics. Since no PDE is solved for re-distancing, the method does not have a stability time step restriction, which is particularly useful in combination with AMR, used here to efficiently resolve fine interface features. In addition, the method can robustly handle discontinuities in the distance function without explicit utilization of solution limiters. Results will be shown for a number of different interface geometries, which will demonstrate the method’s capability of obtaining high-fidelity results on arbitrary meshes.

scholarly journals A Note on a Meshless Method for Fractional Laplacian at Arbitrary Irregular Meshes

Mathematics ◽  
2021 ◽  
Vol 9 (22) ◽  
pp. 2843
Author(s):  
Ángel García ◽  
Mihaela Negreanu ◽  
Francisco Ureña ◽  
Antonio M. Vargas
Keyword(s):  
Cauchy Problem ◽  
Porous Medium ◽  
Meshless Method ◽  
Existence And Uniqueness ◽  
Fractional Laplacian ◽  
Porous Medium Equation ◽  
Medium Equation ◽  
The Cauchy Problem ◽  
Irregular Meshes ◽  
Complicated Geometry

The existence and uniqueness of the discrete solutions of a porous medium equation with diffusion are demonstrated. The Cauchy problem contains a fractional Laplacian and it is equivalent to the extension formulation in the sense of trace and harmonic extension operators. By using the generalized finite difference method, we obtain the convergence of the numerical solution to the classical/theoretical solution of the equation for nonnegative initial data sufficiently smooth and bounded. This procedure allows us to use meshes with complicated geometry (more realistic) or with an irregular distribution of nodes (providing more accurate solutions where needed). Some numerical results are presented in arbitrary irregular meshes to illustrate the potential of the method.

scholarly journals Modelling Spatiotemporal Dynamics of Large Wood Recruitment, Transport, and Deposition at the River Reach Scale during Extreme Floods

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1134 ◽  
Author(s):  
Andreas Zischg ◽  
Niccolo Galatioto ◽  
Silvana Deplazes ◽  
Rolf Weingartner ◽  
Bruno Mazzorana
Keyword(s):  
Simulation Model ◽  
Transport Model ◽  
Large Wood ◽  
Flow Paths ◽  
Extreme Floods ◽  
Reliable Assessment ◽  
Extreme Flood ◽  
Floodplain Inundation ◽  
Irregular Meshes ◽  
River Reach

Large wood (LW) can lead to clogging at bridges and thus cause obstruction, followed by floodplain inundation. Moreover, colliding logs can cause severe damage to bridges, defense structures, and other infrastructure elements. The factors influencing spatiotemporal LW dynamics (LWD) during extreme floods vary remarkably across river basins and flood scenarios. However, there is a lack of methods to estimate the amount of LW in rivers during extreme floods. Modelling approaches allow for a reliable assessment of LW dynamics during extreme flood events by determining LW recruitment, transport, and deposition patterns. Here, we present a method for simulating LWD on a river reach scale implemented in R (LWDsimR). We extended a previously developed LW transport model with a tree recognition model on the basis of Light Detection and Ranging (LiDAR) data for LW recruitment simulation. In addition, we coupled the LWD simulation model with the hydrodynamic simulation model Basic Simulation Environment for Computation of Environmental Flow and Natural Hazard Simulation (BASEMENT-ETH) by adapting the existing LW transport model to be used on irregular meshes. The model has been applied in the Aare River basin (Switzerland) to quantify mobilized LW volumes and the associated flow paths in a probable maximum flood scenario.

Joint Inversion on Irregular Meshes

2018 ◽  
Author(s):  
C. Jordi ◽  
J. Doetsch ◽  
T. Günther ◽  
C. Schmelzbach
Keyword(s):  
Joint Inversion ◽  
Irregular Meshes

scholarly journals Global tide simulations with ICON-O: testing the model performance on highly irregular meshes

2020 ◽  
Vol 71 (1) ◽  
pp. 43-57
Author(s):  
Kai Logemann ◽  
Leonidas Linardakis ◽  
Peter Korn ◽  
Corinna Schrum
Keyword(s):  
General Circulation ◽  
Model Performance ◽  
Circulation Model ◽  
Ocean General Circulation Model ◽  
Discrete Fourier Transformation ◽  
Global Ocean ◽  
Transition Zones ◽  
Maximum Angle ◽  
Irregular Meshes

AbstractThe global tide is simulated with the global ocean general circulation model ICON-O using a newly developed tidal module, which computes the full tidal potential. The simulated coastal M2 amplitudes, derived by a discrete Fourier transformation of the output sea level time series, are compared with the according values derived from satellite altimetry (TPXO-8 atlas). The experiments are repeated with four uniform and sixteen irregular triangular grids. The results show that the quality of the coastal tide simulation depends primarily on the coastal resolution and that the ocean interior can be resolved up to twenty times lower without causing considerable reductions in quality. The mesh transition zones between areas of different resolutions are formed by cell bisection and subsequent local spring optimisation tolerating a triangular cell’s maximum angle up to 84°. Numerical problems with these high-grade non-equiangular cells were not encountered. The results emphasise the numerical feasibility and potential efficiency of highly irregular computational meshes used by ICON-O.

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