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Heat and Mass Transfer

, Volume 34, Issue 6, pp 437–447 | Cite as

Experimental study of water droplet boiling on hot, non-porous surfaces

  • P. Tartarini
  • G. Lorenzini
  • M. R. Randi
Article

Abstract

In this paper, the results of a series of experimental tests on single- and multi-droplet boiling systems are presented and discussed. The main objectives of the present study are: a) to investigate experimentally the effect of the boiling onset on the evaporation rate of water droplets; b) to measure the evolution of the solid surface temperature during evaporation; c) to examine the possibility of improving spray cooling efficiencies. The behavior of small water droplets (from 10 to 50 μl) gently deposited on hot, non-porous surfaces is observed. The evaporation of multi-droplet arrays (50 and 100 μl) under the same conditions of the single-droplet tests is analyzed. In particular, the conditions which determine the onset of nucleate and film boiling are stressed out. In the experimental tests, the interaction of different materials with several multi-droplet systems is monitored by infrared thermography. The spray cooling efficiency is related to the solid temperature decrease as a function of the water mass flux. In the present study, the effect of varying the droplet volume and the mass flux is also analyzed and discussed. The results on the droplets evaporation time and on the solid surface transient temperature distribution are also compared with the data obtained by the same authors during the analysis of droplet evaporation in total absence of nucleate and film boiling. In order to analyze the different behavior of the evaporating droplet as a function of the solid surface thermal conductivity, evaporative transients on aluminum, stainless steel and macor (a glass-like, low-conductivity material) are considered.

Keywords

Solid Surface Mass Flux Water Droplet Transient Temperature Infrared Thermography 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • P. Tartarini
    • 1
  • G. Lorenzini
    • 2
  • M. R. Randi
    • 2
  1. 1.Department of Engineering Sciences Faculty of Engineering University of Modena Via Campi, 213/B I-41100 Modena, ItalyIT
  2. 2.Department of Energetics and Nuclear and Environmental Engineering Faculty of Engineering University of Bologna Viale Risorgimento, 2 I-40136 Bologna, ItalyIT

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