Multiphase Science and Technology A Quarterly

ISSN for PRINT: 0276-1459

For Online Access

Best Paper Award Selection - Editorial Board Site

2007, Volume19

Issue 3

95 pages

DOI: 10.1615/MultScienTechn.v19.i3

Issue price - $193.00

Vishwas V. Wadekar
Heat Transfer and Fluid Flow Service (HTFS), AEA Technology, Harwell Laboratory, Oxfordshire 0X11 ORA, UK

K. M. Miller
HTFS, Aspen Technology, Reading, UK

M. E. D. Urso
HTFS, Aspen Technology, Reading, UK

The article reports pressure drop data for iso-octane boiling in vertical upflow in a 8-m-long, 25.4-mm i.d. tube, heated by direct electrical heating. The trends of the measured pressure gradient are checked with respect to vapor quality, mass flux, and pressure. After confirming that these trends are systematic, the two-phase pressure drop data are examined in terms of their constituent parts, namely, acceleration, friction, and gravity components. Subsequently, the data dominated by the gravity component are used to back-calculate void fractions, and these are compared with various correlations, including the HTFS void fraction method. Some correlations performed better than others in predicting the void fraction data. It is observed that generally, the measured void fraction is lower than expected in the high vapor quality region, even when the quality approaches near-dryout value. To explain this behavior, a simple model is constructed to calculate void fraction as a function of local vapor quality in the postdryout region.

DOI: 10.1615/MultScienTechn.v19.i3.10 Download article, 211-223 pages

Article price - $45.00

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