Theoretical analysis of pressure-drop type instabilities in an upflow boiling system with an exit restriction

L. Cao, S. Kakaç, H. T. Liu, P. K. Sarma

Research output: Contribution to journalArticle

9 Scopus citations

Abstract

In this work, two-phase flow pressure-drop type instabilities in an upflow boiling system are studied theoretically. Dynamic simulations of the pressure-drop type instabilities require the knowledge of the steady state characteristics of the system in terms of the pressure drop versus the mass flow rate. In a boiling system with an exit restriction at the outlet of the boiling channel, the pressure drop through the system concentrates at the exit restriction. Therefore, the correlation of the pressure drop of the two-phase mixture flowing through the exit restriction (i.e. a sharp-edged orifice) is essential in the calculation of the total pressure drop of the system. A model for the exit restriction is developed and compared with the experimental results covering a wide range of vapor quality with different heat inputs and inlet subcoolings. The drift-flux model is adopted to predict the steady state characteristics of the boiling system. The dynamic oscillations of the quasi-static pressure-drop type i nstabilities in the boiling system are simulated and good predictions of the system stability boundary and oscillatory characteristics are obtained when compared with the experimental results.

Original languageEnglish (US)
Pages (from-to)475-483
Number of pages9
JournalHeat and Mass Transfer/Waerme- und Stoffuebertragung
Volume37
Issue number4-5
DOIs
StatePublished - Jul 1 2001

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Fluid Flow and Transfer Processes

Fingerprint Dive into the research topics of 'Theoretical analysis of pressure-drop type instabilities in an upflow boiling system with an exit restriction'. Together they form a unique fingerprint.

  • Cite this