Volume-Agglomeration Coarse Grid In Schwarz Algorithm

2011 ◽  
pp. 3-11
Author(s):  
H. Alcin ◽  
O. Allain ◽  
A. Dervieux
Keyword(s):  
Coarse Grid ◽  
Schwarz Algorithm

A SCHWARZ ALGORITHM FOR THREE-DIMENSIONAL DIFFRACTION PROBLEMS

2015 ◽  
Vol 74 (1) ◽  
pp. 1-8
Author(s):  
M.A. Gnatyuk ◽  
V.M. Morozov ◽  
A.M. Sjanov
Keyword(s):  
Three Dimensional ◽  
Schwarz Algorithm

Exploitation of coarse grid for electromagnetic optimization

2002 ◽  
Author(s):  
J.W. Bandler ◽  
R.M. Biernacki ◽  
S.H. Chen ◽  
P.A. Grobelny ◽  
R.H. Hemmers
Keyword(s):  
Coarse Grid

scholarly journals Flow Simulation Using Local Grid Refinements to Model Laminated Reservoirs

2018 ◽  
Vol 73 ◽  
pp. 5 ◽  
Author(s):  
Manuel Gomes Correia ◽  
Célio Maschio ◽  
Denis José Schiozer
Keyword(s):  
Simulation Model ◽  
Dynamic Properties ◽  
Flow Behavior ◽  
Flow Simulation ◽  
Coarse Grid ◽  
Thin Layers ◽  
Static Properties ◽  
Dynamic Representation ◽  
Medium Flow ◽  
Local Grid

Super-giant carbonate fields, such as Ghawar, in Saudi Arabia, and Lula, at the Brazilian pre-salt, show highly heterogeneous behavior that is linked to high permeability intervals in thin layers. This article applies Local Grid Refinements (LGR) integrated with upscaling procedures to improve the representation of highly laminated reservoirs in flow simulation by preserving the static properties and dynamic trends from geological model. This work was developed in five main steps: (1) define a conventional coarse grid, (2) define LGR in the conventional coarse grid according to super-k and well locations, (3) apply an upscaling procedure for all scenarios, (4) define LGR directly in the simulation model, without integrate geological trends in LGR and (5) compare the dynamic response for all cases. To check results and compare upscaling matches, was used the benchmark model UNISIM-II-R, a refined model based on a combination of Brazilian Pre-salt and Ghawar field information. The main results show that the upscaling of geological models for coarse grid with LGR in highly permeable thin layers provides a close dynamic representation of geological characterization compared to conventional coarse grid and LGR only near-wells. Pseudo-relative permeability curves should be considered for (a) conventional coarse grid or (b) LGR scenarios under dual-medium flow simulations as the upscaling of discrete fracture networks and dual-medium flow models presents several limitations. The conventional approach of LGR directly in simulation model, presents worse results than LGR integrated with upscaling procedures as the extrapolation of dynamic properties to the coarse block mismatch the dynamic behavior from geological characterization. This work suggests further improvements for results for upscaling procedures that mask the flow behavior in highly laminated reservoirs.

A Combined Global Coarsening Method for 3D Multigrid Applications

2012 ◽  
Vol 236-237 ◽  
pp. 1049-1053
Author(s):  
Zong Zhe Li ◽  
Zheng Hua Wang ◽  
Lu Yao ◽  
Wei Cao
Keyword(s):  
Aspect Ratio ◽  
Present Method ◽  
Unstructured Grid ◽  
Unstructured Grids ◽  
Coarse Grid ◽  
3D Flow ◽  
High Quality ◽  
Coarse Grids

An automatic agglomeration methodology to generate coarse grids for 3D flow solutions on anisotropic unstructured grids has been introduced in this paper. The algorithm combines isotropic octree based coarsening and anisotropic directional agglomeration to yield a desired coarsening ratio and high quality of coarse grids, which developed for cell-centered multigrid applications. This coarsening strategy developed is presented on an unstructured grid over 3D ONERA M6 wing. It is shown that the present method provides suitable coarsening ratio and well defined aspect ratio cells at all coarse grid levels.

scholarly journals Distributing Load Flow Computations Across System Operators Boundaries Using the Newton–Krylov–Schwarz Algorithm Implemented in PETSc

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2910
Author(s):  
Stefano Rinaldo  ◽  
Andrea Ceresoli  ◽  
Domenico Lahaye  ◽  
Marco Merlo  ◽  
Miloš  Cvetković ◽  
...  
Keyword(s):  
Power Flow ◽  
Flow Analysis ◽  
Flow Simulation ◽  
Load Flow ◽  
Inexact Newton Method ◽  
Test Case ◽  
Flow Solver ◽  
Cross Border ◽  
System Operator ◽  
Schwarz Algorithm

The upward trends in renewable energy penetration, cross-border flow volatility and electricity actors’ proliferation pose new challenges in the power system management. Electricity and market operators need to increase collaboration, also in terms of more frequent and detailed system analyses, so as to ensure adequate levels of quality and security of supply. This work proposes a novel distributed load flow solver enabling for better cross border flow analysis and fulfilling possible data ownership and confidentiality arrangements in place among the actors. The model exploits an Inexact Newton Method, the Newton–Krylov–Schwarz method, available in the portable, extensible toolkit for scientific computation (PETSc) libraries. A case-study illustrates a real application of the model for the TSO–TSO (transmission system operator) cross-border operation, analyzing the specific policy context and proposing a test case for a coordinated power flow simulation. The results show the feasibility of performing the distributed calculation remotely, keeping the overall simulation times only a few times slower than locally.

Sensitivity-Coefficient Based Inverse Heat Conduction Method for Identifying Hot Spots in Electronics Packages: A Comparison of Grid-Refinement Methods

2021 ◽  
Author(s):  
Patrick Krane ◽  
David Gonzalez Cuadrado ◽  
Francisco Lozano ◽  
Guillermo Paniagua ◽  
Amy Marconnet
Keyword(s):  
Heat Conduction ◽  
Hot Spots ◽  
Computation Time ◽  
Grid Method ◽  
Sensitivity Coefficient ◽  
Coarse Grid ◽  
Inverse Heat Conduction ◽  
Fine Grid ◽  
Temperature Maps ◽  
Electronics Packages

Abstract Estimating the distribution and magnitude of heat generation within electronics packages is pivotal for thermal packaging design and active thermal management systems. Inverse heat conduction methods can provide estimates using measured temperature profiles acquired using infrared imaging or discrete temperature sensors. However, if the heater locations are unknown, applying a fine grid of potential heater locations across the surface where heat generation is expected can result in prohibitively-large computation times. In contrast, using a more computationally-efficient coarse grid can reduce the accuracy of heat flux estimations. This paper evaluates two methods for reducing computation time using a sensitivity-coefficient method for solving the inverse heat conduction problem. One strategy uses a coarse grid that is refined near the hot spots, while the other uses a fine grid of potential heaters only near the hot spots. These grid-refinement methods are compared using both input temperature maps acquired from a "numerical experiment" (where the outputs of a 3D steady-state thermal model in FloTHERM are used for input temperatures) and temperature maps procured using infrared microscopy on a real electronics package. Compared to the coarse-grid method, the fine-grid method reduces computation time without significantly reducing accuracy, making it more convenient for designing and testing electronics packages. It also avoids the problem of "false hot spots" that occurs with the coarse-grid method. Overall, this approach provides a mechanism to predict hot spot locations during design and testing and a tool for active thermal management.

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