Efficient computation of unsteady viscous flows by an implicit preconditioned multigrid method

The development and validation of a parallel unstructured non-nested multigrid method for simulation of unsteady incompressible viscous flow is presented. The Navier-Stokes solver is based on the artificial compressibility method (ACM) [10] and a higher-order characteristics-based finite-volume scheme [8] on unstructured multigrids. Unsteady flow is calculated with an implicit dual time stepping scheme. The parallelization of the solver is achieved by a multigrid domain decomposition approach (MG-DD), using the Single Program Multiple Data (SPMD) programming paradigm and Message-Passing Interface (MPI) for communication of data. The parallel codes using single grids and multigrids are used to simulate steady and unsteady incompressible viscous flows over a circular cylinder for validation and performance evaluation purposes. Speedups and parallel efficiencies obtained by both the parallel single-grid and multigrid solvers are reasonably good for both test cases, using up to 32 processors on the SGI Origin 2000. A maximum speedup of 12 could be achieved on 16 processors for the unsteady flow. The parallel results obtained agree well with those of serial solvers and with numerical solutions obtained by other researchers, as well as experimental measurements.

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A multigrid method for viscous flows for all Mach numbers and all grid aspect ratios

10.2514/6.2000-2255 ◽

2000 ◽

Cited By ~ 1

Author(s):

Jan Vierendeels ◽

Kris Riemslagh ◽

Erik Dick

Keyword(s):

Multigrid Method ◽

Viscous Flows ◽

Aspect Ratios ◽

Mach Numbers

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Efficient computation of unsteady planar internal viscous flows with moving geometry

10.2514/6.1996-113 ◽

1996 ◽

Cited By ~ 3

Author(s):

John Slater

Keyword(s):

Viscous Flows ◽

Efficient Computation

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No fear of George Kingsley Zipf

Instructed Second Language Acquisition ◽

10.1558/37291 ◽

2018 ◽

Vol 2 (2) ◽

pp. 242-263

Author(s):

Stefano Rastelli ◽

Kook-Hee Gil

Keyword(s):

Minimalist Program ◽

Classroom Research ◽

Language Design ◽

Efficient Computation ◽

Generative Linguistics ◽

The Third ◽

Factor Effect ◽

Language Classroom ◽

Recent Developments ◽

Insight Into

This paper offers a new insight into GenSLA classroom research in light of recent developments in the Minimalist Program (MP). Recent research in GenSLA has shown how generative linguistics and acquisition studies can inform the language classroom, mostly focusing on what linguistic aspects of target properties should be integrated as a part of the classroom input. Based on insights from Chomsky’s ‘three factors for language design’ – which bring together the Faculty of Language, input and general principles of economy and efficient computation (the third factor effect) for language development – we put forward a theoretical rationale for how classroom research can offer a unique environment to test the learnability in L2 through the statistical enhancement of the input to which learners are exposed.

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