Fully Threaded Tree for Adaptive Refinement Fluid Dynamics Simulations,

Abstract

A fully threaded tree (FTT) for adaptive refinement of regular meshes is described. By using a tree threaded at all levels, tree traversals for finding nearest neighbors are avoided. All operations on a tree including tree modifications are O(N), where N is a number of cells, and are performed in parallel. An efficient implementation of the tree is described that requires 2N words of memory. A filtering algorithm for removing high frequency noise during mesh refinement is described. A FTT can be used in various numerical applications. In this paper, it is applied to the integration of the Euler equations of fluid dynamics. An adaptive mesh time stepping algorithm is described in which different time steps are used at different levels of the tree. Time stepping and mesh refinement are interleaved to avoid extensive buffer layers of fine mesh which were otherwise required ahead of moving shocks. Test examples are presented, and the FTT performance is evaluated. The three dimensional simulation of the interaction of a shock wave and a spherical bubble is carried out that shows the development of azimuthal perturbations on the bubble surface.

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Document Details

Document Type
Technical Report
Publication Date
May 30, 1997
Accession Number
ADA326280

Entities

People

  • A. M. Khokhlov

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Algorithms
  • Computational Fluid Dynamics
  • Computational Science
  • Computations
  • Computers
  • Differential Equations
  • Dynamics
  • Equations
  • Euler Equations
  • Fluid Dynamics
  • Fluid Flow
  • Frequency
  • Shock
  • Shock Waves
  • Simulations
  • Three Dimensional
  • Two Dimensional

Readers

  • Computational Fluid Dynamics (CFD)
  • Graph Algorithms and Convex Optimization.
  • Parallel and Distributed Computing.