Effective Viscosity in the Simulation of Spatially Evolving Shear Flows with Monotonic FCT Models

Abstract

The global numerical diffusion of a model for the low-Mach-number simulation of free mixing layers is investigated. The numerical model solve the inviscid time-dependent conversation equations for mass, momentum and energy, for ideal gases. The equations are solved using an explicit Flux-Corrected Transport (FCT) algorithm, directional timestep-splitting techniques on structured grids, and appropriate inflow and outflow boundary conditions. Effective measurement of the numerical diffusion of the model in uniform grids is performed by comparison of the laminar spread of the simulated mixing layers with that predicted by boundary layer theory. The results show that the residual numerical diffusion of the FCT model can emulate physical viscosity for laminar shear flows at moderately high Reynolds numbers. The global numerical diffusion is not very sensitive to changes in free-stream velocity ratio, and can be reduced in a predictable way be refining the grid spacing.

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Document Details

Document Type
Technical Report
Publication Date
Dec 13, 1991
Accession Number
ADA243709

Entities

People

  • F. F. Grinstein
  • R. H. Guirguis

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Boundaries
  • Boundary Layer
  • Computational Fluid Dynamics
  • Computational Science
  • Convection
  • Equations
  • Flow
  • Fluid Dynamics
  • Free Stream
  • Mach Number
  • Physics
  • Reynolds Number
  • Shear Flow
  • Simulations
  • Steady State
  • Turbulent Mixing
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Computational Modeling and Simulation
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Fluid Mechanics and Fluid Dynamics.

Technology Areas

  • Space
  • Space - Hall-Effect Thruster