National Technical Reports Library - NTRL

National Technical Reports Library

The National Technical Information Service acquires, indexes, abstracts, and archives the largest collection of U.S. government-sponsored technical reports in existence. The NTRL offers online, free and open access to these authenticated government technical reports. Technical reports and documents in its repository may be available online for free either from the issuing federal agency, the U.S. Government Publishing Office’s Federal Digital System website, or through search engines.




Details
Actions:
Download PDFDownload XML
Download

Large Scale Eigenvalue Calculations for Computing the Stability of Buoyancy Driven Flows.


DE2001782594

Publication Date 2001
Personal Author Burroughs, ; Romero, ; Lehoucq, ; Salinger,
Page Count 49
Abstract We present results for large scale linear stability analysis of buoyancy driven fluid flows using a parallel finite element CFD code (MPSalsa) along with a general purpose eigensolver (ARPACK). The goal of this paper is to examine both the capabilities and limitations of such an approach, with particular focus on solving large problems on massively parallel computers using iterative methods. We accomplish our goal by solving a large vari- ety of two and three dimensional problems of varying difficulty, comparing our results (whenever possible) to semi-analytical results. We also care- fully explain how we successfully combined Cayley transformations with an Arnoldi based eigensolver and preconditioned Krylov methods for the necessary linear solves. For problems where the advective terms are not significant, we achieve excellent convergence of the computed eigenvalues as we refine the finite element mesh. We also successfully solve advectively dominated problems, but the convergence is slower. We believe that the main difficulties arise not from problems with the eigensolver, but from the accuracy of the finite element discretization. Therefore, we believe that our results are as reliable as using transient integration but are more efficiently computed. The largest eigenvalue problem we solve has over 16 million unknowns on 2048 processors.
Keywords
  • Buoyancy
  • Fluid flow
  • Eigenvalues
  • Stability
  • Calculation methods
Source Agency
  • Technical Information Center Oak Ridge Tennessee
Corporate Authors Sandia National Labs., Albuquerque, NM.; Sandia National Labs., Albuquerque, NM.
Document Type Technical Report
NTIS Issue Number 200125
Contract Number
  • AC04-94AL85000
Large Scale Eigenvalue Calculations for Computing the Stability of Buoyancy Driven Flows.
Large Scale Eigenvalue Calculations for Computing the Stability of Buoyancy Driven Flows.
DE2001782594

  • Buoyancy
  • Fluid flow
  • Eigenvalues
  • Stability
  • Calculation methods
  • Technical Information Center Oak Ridge Tennessee
  • AC04-94AL85000
Loading