Journal Article•
On the stability of boiling heat transfer
TL;DR: In this article, the authors derived the maximum and minimum heat-transfer rates in the nucleate and the film-boiling regimes, respectively, using the classical results of Helmholtz Kelvan and Rayleigh expressions.
Abstract: Boiling heat transfer in the nucleate region is reviewed The transition film-boiling region is analyzed by considering the stability of a plane vortex sheet separating two inviscid fluids Using the classical results of Helmholtz Kelvan and Rayleigh expressions have been derived that predict the maximum and minimum heat-transfer rates in the nucleate and the film-boiling regimes, respectively The model exhibits the essential features of the phenomenon and shows good agreement with experimental data (auth)
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TL;DR: In this paper, a review examines recent advances made in predicting boiling heat fluxes, including some key results from the past, including nucleate boiling, maximum heat flux, transition boiling, and film boiling.
Abstract: ▪ Abstract This review examines recent advances made in predicting boiling heat fluxes, including some key results from the past. The topics covered are nucleate boiling, maximum heat flux, transition boiling, and film boiling. The review focuses on pool boiling of pure liquids, but flow boiling is also discussed briefly.
575 citations
TL;DR: The most popular models to predict the two-phase flow dynamic instabilities, namely the homogenous flow model and the drift-flux models are clarified with the solution examples and the validation of the model results with experimental findings are also provided.
378 citations
TL;DR: In this article, a detailed and thorough parametric study of the Leidenfrost point (LFP) is presented, which serves as the temperature boundary between the transition and film boiling regimes.
Abstract: 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
361 citations
TL;DR: In this article, it is shown that the same equations which predict the heat-transfer coefficient and the average turbulent velocity fluctuation in natural turbulent convection from a horizontal surface can be used in the regime of isolated bubbles if the vapor void coefficient i.e. the vapor hold-up is taken into account in evaluating the mean density of the fluid.
357 citations
TL;DR: In this paper, a comprehensive review of published articles addressing passive enhancement of pool boiling using surface modification techniques is provided, including macroscale, microscale, and nanoscale surfaces, as well as multiscale (hybrid-scale), and hybrid-wettability techniques.
343 citations