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Atomization and Sprays

Journal of the International Institutes for Liquid Atomization and Spray Systems

ISSN for PRINT: 1045-5110

Institutional price:	$787.00
Issues per year:	8

Best Paper Award Selection - Editorial Board Site

2007, Volume17

113 pages

Issue price - $109.00

CHARACTERISTICS OF WATER DROPLET IMPACTION BEHAVIOR ON A POLISHED STEEL HEATED SURFACE: PART I

S. W. Akhtar
Institute for Nuclear Power, P.O. Box 3140, Islamabad, Pakistan

G. G. Nasr
Spray Research Group (SRG), Insititute of Materials Research (IMR), School of Computing, Science and Engineering, University of Salford, Manchester, UK

Andrew J. Yule
Spray Research Group (SRG), Insititute of Materials Research (IMR), School of Computing, Science and Engineering, University of Salford, Manchester, UK

ABSTRACT

This paper, which is in two parts, presents the results and analysis of droplet impaction on a hot stainless steel surface. Part I of this study reports the results of analysis of high-speed visualizations of droplet impaction phenomena on a hot stainless steel surface, including the characteristics of reatomized droplets that are produced at high impact Weber numbers. The investigation extends to ranges of smaller droplets and higher velocities compared with published research. Part II will then provide the results and analysis of the droplet impaction heat transfer on a hot surface. The 3.0 mm diameter flat stainless steel surface was heated to temperatures of 140°C < T_w < 400°C, and water sprays were produced from a droplet generation system based on an 80 mm diameter rotary cup. Droplet sizes in the range 20 μm < D < 160 μm were used, impacting with velocities of 5 ms⁻¹ < U < 18 ms⁻¹ . Previous research relevant to the topic is reviewed. Physical models for different forms of droplet breakup in different regimes are developed from the new experiments and compared with existing models. Data are presented for the droplet spreading characteristics, as well as reatomized droplet characteristics, under relatively high impact Weber number conditions (i.e., 100 < We < 750), and for different boiling regimes. These data are correlated well using equations that can be justified by physical arguments.