The Mechanism and the Magnitude of Flow Boiling Augmentation in Tubes with Discrete Surface Roughness Elements (III).

Abstract

Related to other research on the effectiveness of flow boiling heat transfer augmentation using various types of turbulators this investigation comprises a definitive study of the effect of large discrete roughness elements on heat transfer over the entire range of forced convection operation -- from single-phase to critical heat flux. It was found that such elements provide significant augmentation (5-6 times smooth tube levels at equal Reynolds number) in the single-phase and partial boiling modes. However, the augmentation rapidly degrades as the developed boiling mode is entered. Critical heat flux was, in fact, lowered by 15 - 30 percent with the use of the large roughness elements. (Author Modified Abstract)

Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1972
Accession Number
AD0760037

Entities

People

  • Keith L. Truesdale
  • Richard W. Murphy

Organizations

  • Raytheon Missiles & Defense

Tags

DTIC Thesaurus Topics

  • Abstracts
  • Convection
  • Energy Transfer
  • Heat Flux
  • Heat Transfer
  • Physical Properties
  • Reynolds Number
  • Roughness
  • Surface Roughness

Fields of Study

  • Engineering

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Combustion and Flow Dynamics.