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ISSN Online: 2377-424X

ISBN Print: 0-89116-909-1

International Heat Transfer Conference 9
August, 19-24, 1990 , Jerusalem, Israel

TRANSITION BOILING

Get access (open in a dialog) DOI: 10.1615/IHTC9.1850
pages 69-90

Resumo

A review on measuring techniques, experimental results and parametric trends for transition boiling as well as the present knowledge on its mechanism is presented. Emphasis is laid on recent developments and new results. Experiments in transition boiling are complicated but some progress was made towards suitable measuring techniques. No generally valid trends exist for the influence of pressure and mass flux. Increasing subcooling improves the heat transfer in the transition region. This holds also for surface oxidation, coatings and deposition. Increasing surface roughness shifts the boiling curve to lower temperature differences and yields higher critical heat fluxes. The transition region is strongly affected by the effusivity (λρcP) of the material. Transient experiments yield different results than steady−state runs. In general, the difference increases with increasing surface temperature change rate. The overall heat transfer in transition boiling is governed by the heat flux during liquid−solid contact. There is, however, a need for quantitative results about the local heat transfer history on the heating surface. Prediction methods yield large discrepancies. At present for a reasonable estimate the quantities qCHF/ΔTCHF and qMHF/ΔTMHF at the critical boiling point and the minimum film boiling point, respectively, are required.