Characterization of Convective Boiling in Branching Channel Heat Sinks

Abstract

Convective boiling and gas-liquid flows in branching microscale flow networks within disk-shaped heat sinks were studied experimentally. Void fraction and flow regime variations as a function of branch level were reported for gas-liquid flows and compared with existing void fraction correlations and regime maps, respectively. Two methods for assessing void fraction were used, with void fraction assessed using two-dimensional high-speed images providing the best assessment. Void fraction in convective boiling flows showed backflow that would sometimes reroute downstream through an adjacent branch and at other times flow back to the inlet plenum, depending upon the degree of upstream throttling. A technique for measuring convective wall temperatures was developed and used to qualitatively assess temperature variations between vapor and liquid phase contact. Adiabatic flow boiling data was used to validate a one-dimensional, two-phase pressure drop model for use in flow network optimization. Validation of the heat transfer portion of the model was not possible without wall temperature data.

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Document Details

Document Type
Technical Report
Publication Date
May 06, 2009
Accession Number
ADA498349

Entities

People

  • Deborah V. Pence
  • James A. Liburdy
  • Vinod Narayanan

Organizations

  • Oregon State University

Tags

Communities of Interest

  • Advanced Electronics
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Energy
  • Flow
  • Flow Network
  • Flow Visualization
  • Fluid Flow
  • Fluids
  • Geometry
  • Heat Energy
  • Heat Sinks
  • Heat Transfer
  • High Resolution
  • Hydrodynamics
  • Liquid Phases
  • Phase
  • Predictive Modeling
  • Two Dimensional
  • Two Phase Flow

Fields of Study

  • Environmental science

Readers

  • Combustion and Flow Dynamics.
  • Materials Science (Mechanical Engineering).