Surface De-Wetting Based Critical Heat Flux Model Development and Validation

Abstract

Experimental work was undertaken to investigate the critical heat flux (CHF) mechanism in pool boiling. Local temperature and heat transfer coefficient on the heated surface were measured via IR camera. Based on the experimental results, the wetted area fraction and the contact line length density with wall superheat were observed. Also, an analytical work into pool boiling heat transfer was presented to determine the contribution of each region to the overall heat transfer in pool boiling. The heat transfer through the liquid was found to be the dominant heat transfer mechanism due to significantly larger area. While the heat transfer through the liquid determines the overall heat transfer, contact line heat transfer wall is critically important to trigger the onset of CHF. When the process of dewetting occurs at contact line and micro region, the temperature of dry spots increases, hence dryout areas increase and the CHF occurs. Finally, we proposed the CHF mechanism based on the surface dewetting and experimental data.

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Document Details

Document Type
Technical Report
Publication Date
Feb 05, 2013
Accession Number
ADA578387

Entities

People

  • Jungho Kim
  • Sung J. Kim

Organizations

  • KAIST

Tags

Communities of Interest

  • Advanced Electronics
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Coefficients
  • Computers
  • Data Acquisition
  • Energy
  • Experimental Data
  • Films
  • Flow
  • Fluid Mechanics
  • Fluids
  • Heat Energy
  • Heat Flux
  • Heat Transfer
  • Heat Transfer Coefficients
  • Mass Transfer
  • Measurement
  • Surface Temperature
  • Temperature Gradients

Fields of Study

  • Environmental science

Readers

  • Combustion and Flow Dynamics.