Numerical Simulation of the Disturbed Flow Through a Three-Dimensional Building Array

Abstract

A study of the neutrally-stratified flow within and over an array of three-dimensional (3-D) buildings (cubes) was undertaken using simple Reynolds-averaged Navier-Stokes (RANS) flow models. These models consist of a general solution of the ensemble-averaged, steady-state, three-dimensional Navier-Stokes equations, where the k-E turbulence model (k is turbulence kinetic energy and E is viscous dissipation rate) has been used to close the system of equations. Two turbulence closure models were tested; namely, the standard and Kato-Launder k-E models. The latter model is a modified k-E model designed specifically to overcome the stagnation point anomaly in flows past a bluff body where the standard k-E model overpredicts the production of turbulence kinetic energy near the stagnation point. Results of a detailed comparison between a wind tunnel experiment and the RANS flow model predictions are presented. More specifically, vertical profiles of the predicted mean streamwise velocity, mean vertical velocity, and turbulence kinetic energy at a number of streamwise locations that extend from the impingement zone upstream of the array, through the array interior, to the exit region downstream of the array are presented and compared to those measured in the wind tunnel experiment. Generally, the numerical predictions show good agreement for the mean flow velocities. The turbulence kinetic energy was underestimated by the two different closure models. After validation, the results of the high-resolution RANS flow model predictions were used to diagnose the dispersive stress, within and above the building array. The importance of dispersive stresses, which arise from point-to-point variations in the mean flow field, relative to the spatially-averaged Reynolds stresses are assessed for the building array.

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 2004
Accession Number
ADA426319

Entities

People

  • Eugene Yee
  • Fue-sang Lien

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Boundary Layer
  • Computational Fluid Dynamics
  • Differential Equations
  • Flow Fields
  • Fluid Dynamics
  • Fluid Flow
  • Geometry
  • High Resolution
  • Mechanical Properties
  • Navier Stokes Equations
  • Shear Stresses
  • Stagnation Point
  • Steady State
  • Three Dimensional
  • Turbulence
  • Turbulent Mixing
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Computational Fluid Dynamics (CFD)
  • Fluid Mechanics and Fluid Dynamics.