A Study of Mixed Convection in Large Baffled Rectangular Chambers with and without Internal Heat Sources

Abstract

A numerical and experimental investigation to determine the thermal effects on the development of the flow structure in large baffled rectangular chambers with and without internal heat sources has been completed. Two- and three-dimensional numerical models were formulated using the time-dependent laminar Navier-Stokes equations assuming a Boussinesq fluid with a Prandtl number of 0.7. Experiments were conducted using a scaled-down model simulated the full-size chamber enabling experimental data to be obtained and subsequently compared with numerical results. Flow visualization experiments were conducted using the larger, full-size chamber. Internal horizontal baffles and heat sources were located symmetrically about the vertical centerline axis. Mixed convection without internal heat sources for both aided and opposed buoyant forces showed that the development of the flow structure was sensitive to small variations in the temperature difference between the inlet and the vertical walls. Mixed convection with internal heat sources showed the flow structure to develop through a series of bifurcations from steady state, to periodic, aperiodic and finally chaotic with increasing heat source temperature. Use of the scaled down laboratory experimental model as an indicator for the flow development in the larger full-size chamber showed significant three-dimensional effects. Flow visualization in the larger full-size chamber using Silahydrocarbon aerosol droplets showed good agreement with two-dimensional numerical results. Keywords: Mixed convection; Thermal effects; Inhalation toxicology; Flow; Exposure chambers; Internal heat sources; Theoretical; Buoyant; Experimental.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1990
Accession Number
ADA223158

Entities

People

  • K. L. Yerkes

Tags

Communities of Interest

  • Biomedical
  • Energy and Power Technologies
  • Sensors

DTIC Thesaurus Topics

  • Boundary Layer
  • Buoyancy
  • Computational Fluid Dynamics
  • Computational Science
  • Differential Equations
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Flow
  • Fluid Mechanics
  • Heat Transfer
  • Laboratory Animals
  • Materials
  • Measurement
  • Steady State
  • Temperature Gradients
  • Three Dimensional
  • Two Dimensional

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