The Leidenfrost point : Experimental study and assessment of existing models

Recent demands for superior material properties and more efficient use of materials and production time are forcing manufacturers to develop intelligent processing techniques for enhanced process control in order to better dictate the end product. In the heat treatment and processing of metallic alloys, the desire to obtain parts of enhanced and uniform mechanical properties is requiring increased control over heat removal rates and enhanced temperature control. In particular, spray quenching has been shown to be an effective means to control and enhance the cooling rates of heat treatable aluminum alloys. This study presents a detailed and thorough parametric study of the Leidenfrost point (LFP), which serves as the temperature boundary between the transition and film boiling regimes. Sessile drop evaporation experiments were conducted with acetone, benzene, FC-72, and water on heated aluminum surfaces with either polished, particle blasted, or rough sanded finishes to observe the influential effects of fluid properties, surface roughness, and surface contamination on the LFP. A weak relationship between surface energies and the LFP was observed by performing droplet evaporation experiments with water on polished copper, nickel, and silver surfaces. Additional parameters which were investigated and found to have negligible influence on the LFP included liquidmore » subcooling, liquid degassing, surface roughness on the polished level, and the presence of polishing paste residues. The accumulated LFP data of this study were used to assess several existing models which attempt to identify the mechanisms which govern the LFP. The disagreement between the experimental LFP values and those predicted by the various models suggests that an accurate and robust theoretical model which effectively captures the LFP mechanisms is currently unavailable.« less

[1]  Shi-Chune Yao,et al.  The dynamics and leidenfrost temperature of drops impacting on a hot surface at small angles , 1988 .

[2]  E. Hosler.  Film Boiling on a Horizontal Plate , 1962 .

[3]  J. Lienhard.  Correlation for the limiting liquid superheat , 1976 .

[4]  John D. Bernardin,et al.  Validation of the quench factor technique in predicting hardness in heat treatable aluminum alloys , 1995 .

[5]  N. Zuber.  On the Stability of Boiling Heat Transfer , 1958, Journal of Fluids Engineering.

[6]  P. Testa,et al.  Influence of Pressure on the Leidenfrost Temperature and on Extracted Heat Fluxes in the Transient Mode and Low Pressure , 1986 .

[7]  Shigefumi Nishio,et al.  DIRECT CONTACT PHENOMENON BETWEEN A LIQUID DROPLET AND HIGH TEMPERATURE SOLID SURFACE , 1978 .

[8]  Milton Blander.  Bubble nucleation in liquids , 1979 .

[9]  S. Bankoff,et al.  The role of adsorption in determining the minimum film boiling temperature , 1980 .

[10]  A. Adamson.  Potential distortion model for contact angle and spreading. II. Temperature dependent effects , 1973 .

[11]  J. Hirth,et al.  Bubble nucleation , 1970, Metallurgical and Materials Transactions B.

[12]  T. Matsuda,et al.  Energetic properties of nio surface examined by heat-of-adsorption measurement , 1992 .

[13]  Amir Karimi,et al.  Corresponding States Correlations of the Extreme Liquid Superheat and Vapor Subcooling , 1978 .

[14]  George S. Emmerson,et al.  The effect of pressure and surface material on the leidenfrost point of discrete drops of water , 1975 .

[15]  V. G. Labeish.  Thermohydrodynamic study of a drop impact against a heated surface , 1994 .

[16]  S. A. Kovalev.  An investigation of minimum heat fluxes in pool boiling of water , 1966 .

[17]  J. Rozzi,et al.  Film and transition boiling correlations for quenching of hot surfaces with water sprays , 1992 .

[18]  R. Furzeland,et al.  Rapid evaporation at the superheat limit , 1988 .

[19]  Walter S. Bradfield,et al.  On liquid-solid contact in stable film boiling , 1966 .

[20]  J. Westwater,et al.  Nucleation sites for dropwise condensation , 1965 .

[21]  F. A. Wierum,et al.  Liquid spray cooling of a heated surface , 1981 .

[22]  M. C. Yuen,et al.  Evaporation of a liquid droplet on a hot plate , 1991 .

[23]  G. Yadigaroglu,et al.  A local equation of state for a fluid in the presence of a wall and its application to rewetting , 1992 .

[24]  Joseph Katz,et al.  Bubble nucleation in liquids , 1975 .

[25]  J. Katz,et al.  Bubble nucleation in n-pentane, n-hexane and n-pentane + hexadecane mixtures and water , 1971 .

[26]  K. Baumeister,et al.  Leidenfrost temperature - Its correlation for liquid metals, cryogens, hydrocarbons, and water. , 1973 .

[27]  R. Henry,et al.  An Investigation of the Minimum Film Boiling Temperature on Horizontal Surfaces , 1978 .

[28]  P. J. Berenson.  Film-Boiling Heat Transfer From a Horizontal Surface , 1961 .

[29]  C. Avedisian,et al.  Leidenfrost boiling of methanol droplets on hot porous/ceramic surfaces , 1987 .

[30]  A. Adamson.  Physical chemistry of surfaces , 1960 .

[31]  Peter Griffith,et al.  The mechanism of heat transfer in nucleate pool boiling—Part II: The heat flux-temperature difference relation , 1965 .

[32]  Y. Zvirin,et al.  The relation between the rewetting temperature and the liquid-solid contact angle , 1988 .

[33]  L. J. Clarke,et al.  An experimental study of vapour growth at the superheat limit temperature , 1988 .

[34]  R. A. Nelson,et al.  Unifying the controlling mechanisms for the critical heat flux and quenching : the ability of liquid to contact the hot surface , 1992 .

[35]  John D. Bernardin,et al.  Contact angle temperature dependence for water droplets on practical aluminum surfaces , 1997 .

[36]  J. Hopenfeld,et al.  Onset of stable film boiling and the foam limit , 1963 .

[37]  John H. Lienhard,et al.  Transition boiling heat transfer and the film transition regime , 1987 .

[38]  Kenneth J. Bell,et al.  The leidenfrost phenomenon: film boiling of liquid droplets on a flat plate , 1966 .

[39]  V. Klimenko,et al.  Film boiling crisis on a submerged heating surface , 1990 .

[40]  J. Eberhart,et al.  Application of the mechanical stability condition to the prediction of the limit of superheat for normal alkanes, ether, and water , 1973 .

[41]  R. E. Henry,et al.  Role of the surface in the measurement of the Leidenfrost temperature , 1970 .

[42]  E. Eckert,et al.  Analysis of heat and mass transfer , 1971 .

[43]  C. Snoek,et al.  The effect of pressure on the leidenfrost point of discrete drops of water and freon on a brass surface , 1978 .

[44]  G. Taylor.  The instability of liquid surfaces when accelerated in a direction perpendicular to their planes. I , 1950, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.