Modeling Fluid Flow by Exploring Different Flow Geometries and Effect of Weak Compressibility

Abstract

Atmospheric mixing is a problem of exceptional importance and difficult to study. The anelastic approximation is the accepted fluid system governing the atmosphere over large vertical scales (about 8 km). The anelastic equations, unlike the Navier-Stokes equations, incorporate a nontrivial spatial divergence constraint on the velocity field. This yields a weakly compressible fluid flow. The basis of this study is to use numerical analysis to explore the effects of weak compressibility in the evolution of fluid governed by the anelastic equations, and the effects of incompressibility governed by the Navier-Stokes equation. The analysis then goes on to investigate the difference between three different initial conditions. Within each initial condition different density profiles are observed while varying parameters are investigated. Numerical results show that comparisons of incompressible Navier-Stokes equations to the anelastic fluid flow equations do not produce similar results. The weakly compressible flow creates a mixing barrier, stopping vertical fluid exchange. The perturbed middle region initial condition creates a chaotic environment that prevents vortices from merging.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 2006
Accession Number
ADA457678

Entities

People

  • James J. Sopko

Organizations

  • Naval Postgraduate School

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Boundary Layer
  • Computational Fluid Dynamics
  • Computational Science
  • Computer Programs
  • Differential Equations
  • Equations
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Incompressible Flow
  • Mechanical Properties
  • Mechanics
  • Mixing
  • Navier Stokes Equations
  • Numerical Analysis
  • Poiseuille Flow
  • Stratified Fluids

Readers

  • Combustion and Flow Dynamics.
  • Computational Fluid Dynamics (CFD)
  • Linear Algebra