JP Journal of Heat and Mass Transfer
Volume 2, Issue 1, Pages 55 - 71
(February 2008)
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EFFECTS OF PLANAR JET IMPINGEMENT ON SINGLE-PHASE CONVECTION AND BOILING HEAT TRANSFER CHARACTERISTICS
C. H. Shin (Korea), S.-J. Wu (Korea), K. M. Kim (Korea) and H. H. Cho (Korea)
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Abstract: Single-phase convection and nucleate boiling are
investigated for planar subcooled water jets. The degree of spacing between the
jet nozzle plate and heated surface is considered. Detailed wall temperature and
convection coefficient distributions, as well as typical boiling curves, are
discussed. The effects of velocity on single-phase convection coefficients
indicate that the locus of the secondary peak is entirely dependent on
jet turbulence and velocity. The increasing acceleration throughout the
whole channel, with decreasing spacing, precipitates the transition and enhances
convection over the whole region, including the stagnation region. The
difference in convection coefficients decreases significantly with increasing
distance downstream and as boiling develops. However, the strong effect of
impingement on convection maintains the
differences between the free-surface and submerged jets. |
Keywords and phrases: convective boiling, heat transfer, impinging jet, liquid jet, two-phase flow. |
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