scholarly journals Numerical simulation of dropwise condensation over hydrophobic surfaces using vapor-diffusion model

2021 ◽  
Vol 2116 (1) ◽  
pp. 012011
Author(s):  
N Suzzi ◽  
G Croce
Keyword(s):  
Heat Transfer ◽  
Diffusion Model ◽  
Lagrangian Model ◽  
Dropwise Condensation ◽  
Velocity Range ◽  
Air Velocity ◽  
Hydrophobic Surfaces ◽  
Vapor Diffusion ◽  
Condensation Model ◽  
Hydrophilic And Hydrophobic Surfaces

Abstract Dropwise condensation of humid air over hydrophilic and hydrophobic surfaces is numerically investigated using a phenomenological, Lagrangian model. Mass flux through droplets free surface is predicted via a vapor-diffusion model. Validation with literature experimental data is successfully conducted at different air humidities and air velocities. The accuracy of the implemented condensation model is compared with a standard analogy between convective heat and mass transfer, showing that the latter is not able to predict heat transfer performances in the investigated air velocity range.

scholarly journals Modeling Study on Heat Transfer in Marangoni Dropwise Condensation for Ethanol-Water Mixture Vapors

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6726
Author(s):  
Jinshi Wang ◽  
Ziqiang Ma ◽  
Yong Li ◽  
Weiqi Liu ◽  
Gen Li
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Temperature Difference ◽  
Diffusion Layer ◽  
Water Mixture ◽  
Dropwise Condensation ◽  
Heat Transfer Characteristics ◽  
Vapor Diffusion ◽  
Transfer Characteristics ◽  
Condensate Layer

In this paper, a model was developed to predict the heat transfer characteristics of Marangoni dropwise condensation. In accordance with the feature of Marangoni condensation, condensation was treated as dropwise condensation of mixture vapors. The condensation space was divided into two parts: the vapor diffusion layer and the condensate layer. For the condensate layer, the classical heat transfer calculation method of dropwise condensation was imitated to obtain the heat transfer characteristics. For the vapor diffusion layer, the heat transfer characteristics were achieved by solving the conservation equations. These heat transfer characteristics were coupled through the conjunct boundary, which was the vapor-liquid interface. The model was applied to the condensation of water-ethanol mixture vapors. A comparison with the existing experimental data showed that the developed model could basically reflect the influences of vapor-to-surface temperature difference, vapor concentration, vapor pressure, and vapor velocity on heat transfer characteristic of Marangoni condensation. Results showed that some differences existed between the calculation results and experimental results, but the prediction deviation of the model could be acceptable in the range of vapor-to-surface temperature difference where the condensation heat transfer coefficients reached peak values.

Biotemplated Superhydrophobic Surfaces for Enhanced Dropwise Condensation

2012 ◽  
Author(s):  
Emre Olceroglu ◽  
Stephen M. King ◽  
Md. Mahamudur Rahman ◽  
Matthew McCarthy
Keyword(s):  
Heat Transfer ◽  
Large Scale ◽  
Electronics Cooling ◽  
High Heat ◽  
The Self ◽  
High Heat Flux ◽  
Dropwise Condensation ◽  
Large Area ◽  
Hydrophobic Surfaces ◽  
Structured Surfaces

The increased heat transfer achieved through dropwise condensation, as compared to filmwise condensation, has the potential to substantially impact a variety of applications including high-heat flux thermal management systems, integrated electronics cooling, and various industrial and chemical processes. Here, we report stable dropwise condensation onto biotemplated nanostructured super-hydrophobic surfaces. We have demonstrated continuous droplet coalescence and ejection at diameters of less than 20 μm and compared directly with flat hydrophobic surfaces. The self-ejection mechanism characteristic of dropwise condensation has been shown using a simple bio-nano-fabrication technique based on the self-assembly and mineralization of the Tobacco mosaic virus (TMV). This process is extendable to commercially relevant nanomanufacturing of both microscale electronics devices as well as large-scale large-area industrial equipment. This manufacturing flexibility is unique as compared to many other micro/nano-structured surfaces fabricated to demonstrate similar increases in condensation heat transfer.

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