Droplets boiling crisis of ethanol water solution on duralumin substrate with SiO2 nanoparticles coating

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

Boiling crisis and evaporation of droplets of ethanol water solution on a horizontal ceramic heating surface were studied experimentally. The experiment was performed on duralumin substrate with SiO2. The coating was obtained by nanoparticles plasma spraying. Measurements of the contact angle of the aqueous solution onto the ceramic surface were performed. Most evaporation relates to an increase in the area of the wetting droplet surface and only 10-20% of evaporation relates to the effect of diffusion and change in the thermal-physical coefficients. Maximal instability of the bubble microlayer for alcohol solution with C0 = 20-40 mass% is observed. The critical heat flux behaves non-monotonously at a change in alcohol concentration in solution, and there are two extremes. The maximal value of sustainability coefficient at evaporation of droplets of ethanol solution corresponds to alcohol concentration of 20-30 mass%. Concentration gradient leads to instability of a triple contact line at the bubble bottom and a decrease in the dry spot area; this promotes higher critical heat flux levels (CHF). The behavior of a binary mixture depends not only on the Marangoni effect at the droplet edges, as thought previously, but also on the unsustainable behavior of the bubbles contact line. The heat transfer coefficient of ethanol solution in the spheroidal state decreases with a rise of wall overheating and spheroid diameter. Experimental dependence of the vapor layer height on wall overheating at boiling crisis was derived. The height of this layer (60-80 μm) at Leidenfrost temperature manifold exceeds the surface microroughness value (1-1.5 μm).

Original languageEnglish
Pages (from-to)43-53
Number of pages11
JournalExperimental Thermal and Fluid Science
Volume75
DOIs
Publication statusPublished - 1 Jul 2016
Externally publishedYes

Fingerprint

Aluminum copper alloys
Boiling liquids
Ethanol
Nanoparticles
Coatings
Water
Evaporation
Substrates
Alcohols
Heat flux
Plasma spraying
Binary mixtures
Bubbles (in fluids)
Heat transfer coefficients
Contact angle
Wetting
Sustainable development
Vapors
Heating

Keywords

  • Droplets boiling crisis
  • Ethanol water solution
  • Marangoni force
  • Nanoparticles ceramic coating

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Nuclear Energy and Engineering
  • Aerospace Engineering
  • Mechanical Engineering
  • Fluid Flow and Transfer Processes

Cite this

@article{cf8331f8209d4fb0b69aa77da9cc9b82,
title = "Droplets boiling crisis of ethanol water solution on duralumin substrate with SiO2 nanoparticles coating",
abstract = "Boiling crisis and evaporation of droplets of ethanol water solution on a horizontal ceramic heating surface were studied experimentally. The experiment was performed on duralumin substrate with SiO2. The coating was obtained by nanoparticles plasma spraying. Measurements of the contact angle of the aqueous solution onto the ceramic surface were performed. Most evaporation relates to an increase in the area of the wetting droplet surface and only 10-20{\%} of evaporation relates to the effect of diffusion and change in the thermal-physical coefficients. Maximal instability of the bubble microlayer for alcohol solution with C0 = 20-40 mass{\%} is observed. The critical heat flux behaves non-monotonously at a change in alcohol concentration in solution, and there are two extremes. The maximal value of sustainability coefficient at evaporation of droplets of ethanol solution corresponds to alcohol concentration of 20-30 mass{\%}. Concentration gradient leads to instability of a triple contact line at the bubble bottom and a decrease in the dry spot area; this promotes higher critical heat flux levels (CHF). The behavior of a binary mixture depends not only on the Marangoni effect at the droplet edges, as thought previously, but also on the unsustainable behavior of the bubbles contact line. The heat transfer coefficient of ethanol solution in the spheroidal state decreases with a rise of wall overheating and spheroid diameter. Experimental dependence of the vapor layer height on wall overheating at boiling crisis was derived. The height of this layer (60-80 μm) at Leidenfrost temperature manifold exceeds the surface microroughness value (1-1.5 μm).",
keywords = "Droplets boiling crisis, Ethanol water solution, Marangoni force, Nanoparticles ceramic coating",
author = "Misyura, {S. Y.}",
year = "2016",
month = "7",
day = "1",
doi = "10.1016/j.expthermflusci.2016.01.015",
language = "English",
volume = "75",
pages = "43--53",
journal = "Experimental Thermal and Fluid Science",
issn = "0894-1777",
publisher = "Elsevier Inc.",

}

TY - JOUR

T1 - Droplets boiling crisis of ethanol water solution on duralumin substrate with SiO2 nanoparticles coating

AU - Misyura, S. Y.

PY - 2016/7/1

Y1 - 2016/7/1

N2 - Boiling crisis and evaporation of droplets of ethanol water solution on a horizontal ceramic heating surface were studied experimentally. The experiment was performed on duralumin substrate with SiO2. The coating was obtained by nanoparticles plasma spraying. Measurements of the contact angle of the aqueous solution onto the ceramic surface were performed. Most evaporation relates to an increase in the area of the wetting droplet surface and only 10-20% of evaporation relates to the effect of diffusion and change in the thermal-physical coefficients. Maximal instability of the bubble microlayer for alcohol solution with C0 = 20-40 mass% is observed. The critical heat flux behaves non-monotonously at a change in alcohol concentration in solution, and there are two extremes. The maximal value of sustainability coefficient at evaporation of droplets of ethanol solution corresponds to alcohol concentration of 20-30 mass%. Concentration gradient leads to instability of a triple contact line at the bubble bottom and a decrease in the dry spot area; this promotes higher critical heat flux levels (CHF). The behavior of a binary mixture depends not only on the Marangoni effect at the droplet edges, as thought previously, but also on the unsustainable behavior of the bubbles contact line. The heat transfer coefficient of ethanol solution in the spheroidal state decreases with a rise of wall overheating and spheroid diameter. Experimental dependence of the vapor layer height on wall overheating at boiling crisis was derived. The height of this layer (60-80 μm) at Leidenfrost temperature manifold exceeds the surface microroughness value (1-1.5 μm).

AB - Boiling crisis and evaporation of droplets of ethanol water solution on a horizontal ceramic heating surface were studied experimentally. The experiment was performed on duralumin substrate with SiO2. The coating was obtained by nanoparticles plasma spraying. Measurements of the contact angle of the aqueous solution onto the ceramic surface were performed. Most evaporation relates to an increase in the area of the wetting droplet surface and only 10-20% of evaporation relates to the effect of diffusion and change in the thermal-physical coefficients. Maximal instability of the bubble microlayer for alcohol solution with C0 = 20-40 mass% is observed. The critical heat flux behaves non-monotonously at a change in alcohol concentration in solution, and there are two extremes. The maximal value of sustainability coefficient at evaporation of droplets of ethanol solution corresponds to alcohol concentration of 20-30 mass%. Concentration gradient leads to instability of a triple contact line at the bubble bottom and a decrease in the dry spot area; this promotes higher critical heat flux levels (CHF). The behavior of a binary mixture depends not only on the Marangoni effect at the droplet edges, as thought previously, but also on the unsustainable behavior of the bubbles contact line. The heat transfer coefficient of ethanol solution in the spheroidal state decreases with a rise of wall overheating and spheroid diameter. Experimental dependence of the vapor layer height on wall overheating at boiling crisis was derived. The height of this layer (60-80 μm) at Leidenfrost temperature manifold exceeds the surface microroughness value (1-1.5 μm).

KW - Droplets boiling crisis

KW - Ethanol water solution

KW - Marangoni force

KW - Nanoparticles ceramic coating

UR - http://www.scopus.com/inward/record.url?scp=84957882345&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84957882345&partnerID=8YFLogxK

U2 - 10.1016/j.expthermflusci.2016.01.015

DO - 10.1016/j.expthermflusci.2016.01.015

M3 - Article

VL - 75

SP - 43

EP - 53

JO - Experimental Thermal and Fluid Science

JF - Experimental Thermal and Fluid Science

SN - 0894-1777

ER -