An original concept for the synthesis of an oxide coating: The film boiling process

Besnard, Cyril; Allemand, A.; David, Patrick; León, Jaimes; Maillé, Laurence

doi:10.1016/j.jeurceramsoc.2020.10.069

Cited by 4 publications

(2 citation statements)

References 58 publications

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“…Another method is to accelerate chemical deposition kinetics through the increase in the gaseous reactant partial pressure. This is made possible as soon as a sufficient thermal gradient is present, for example in the film-boiling process [13][14][15][16] in which the exterior part of the fibrous preform is in contact with the boiling precursor, thereby maintaining a strong thermal gradient inside it. In this TG-CVI variation, the external pressure is ambient instead of the reduced pressure necessary for the correct infiltration in I-CVI conditions.…”

Section: Introductionmentioning

confidence: 99%

Chemical Supercritical Fluid Infiltration of Pyrocarbon with Thermal Gradients: Deposition Kinetics and Multiphysics Modeling

et al. 2022

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The chemical supercritical fluid infiltration process is a recent variation of the chemical vapor infiltration (CVI) process that allows rapid and efficient manufacturing of ceramic-matrix composites (CMCs), albeit still needing optimization. This article proposes a quantitative assessment of the process dynamics through experiments and modeling. The kinetics of carbon deposition were determined through two sets of experiments: CVD on a single filament at pressures between 10 and 50 bar and infiltration at pressures ranging between 50 and 120 bar. The CVI experiments were conducted under important thermal gradients and were interpreted using a model-based reconstitution of these gradients. We found that (i) the kinetic law has to incorporate the potential effect of the reverse reaction (i.e., etching of C by H2); (ii) the activation energy and pre-exponential factor both decrease with pressure up to 50 bar, then remain roughly constant, and (iii) although the apparent activation energy is modest, a favorable situation occurs in which an infiltration front builds up and travels from the hottest to the coldest part of the preform due to the presence of sufficient heat flux. A numerical simulation of the process, based on the solution of momentum, heat, and mass balance equations, fed with appropriate laws for the effective transfer properties of the porous medium and their evolution with infiltration progress, was performed and validated by comparing the simulated and actual infiltration profiles.

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Section: Introductionmentioning

confidence: 99%

Chemical Supercritical Fluid Infiltration of Pyrocarbon with Thermal Gradients: Deposition Kinetics and Multiphysics Modeling

et al. 2022

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“…Boiling is a pervasive phase transition phenomenon and has widespread industrial applications, such as power generation, microelectronic device cooling, , and chemical processing . Especially in the energy conversion and utilization systems, boiling processes are widely utilized for enhancing heat transfer performance; thus, it is of great significance to acquire more rapid and efficient boiling for the improvement of energy efficiency.…”

Section: Introductionmentioning

confidence: 99%

Nanoscale Thin-Film Boiling Processes on Heterogeneous Surfaces

Gao

Liu

et al. 2022

Langmuir

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Acquiring rapid and efficient boiling processes has been the focus of industry as they have the potential to improve the energy efficiency and reduce the carbon emissions of production processes. Here, we report nanoscale thin-film boiling on different heterogeneous surfaces. Through nonequilibrium molecular dynamics simulation, we captured the triple-phase interface details, visualized the bubble nucleation, and recorded the internal fluid flow and thermal characteristics. It is found that nanoscale thin-film boiling without the occurrence of bubble nucleation shows excellent heat and mass transfer performance, which differs from macroscale boiling. In general, rough structures advance the onset time of stable boiling and improve the efficiency. The heat transfer coefficient and heat flux on a rough hydrophilic surface respectively reach to 7.43 × 104 kW/(m2·K) and 1.3 × 106 kW/m2 at a surface temperature of 500 K, which are 100-fold higher than those of micrometer-scale thin-film boiling. However, due to the resultant vapor film trapped between the liquid and the surface, the rough hydrophobic surface leads to heat transfer deterioration instead. It is revealed that the underlying mechanism of regulatory effects resulting from surface physicochemical properties is originated from the variation of interfacial thermal resistance. It is available to reduce the overall interfacial resistance and further improve the heat and mass transfer efficiency through increasing surface roughness, enhancing surface wettability, and increasing the area proportion of the hydrophilic region. This work provides guidelines to achieve rapid and efficient thin-liquid-film boiling and serves as a reference for the optimized design of surfaces utilized for high-heat flux removal through vaporization processes.

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Review of surface modification in pool boiling application: Coating manufacturing process and heat transfer enhancement mechanism

Chu

et al. 2022

Applied Thermal Engineering

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An original concept for the synthesis of an oxide coating: The film boiling process

Cited by 4 publications

References 58 publications

Chemical Supercritical Fluid Infiltration of Pyrocarbon with Thermal Gradients: Deposition Kinetics and Multiphysics Modeling

Chemical Supercritical Fluid Infiltration of Pyrocarbon with Thermal Gradients: Deposition Kinetics and Multiphysics Modeling

Nanoscale Thin-Film Boiling Processes on Heterogeneous Surfaces

Review of surface modification in pool boiling application: Coating manufacturing process and heat transfer enhancement mechanism

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