Experimental study on preparation of nanoparticle-surfactant nanofluids and their effects on coal surface wettability

The evaporation of sessile drop has a wide range of application that includes printing, washing, cooling, and coating. Due to the complex nature of drop evaporation process, this phenomenon is reliant on several parameters such as ambiance and physiochemical properties of liquid and surface. In the present study, a mathematical model of water droplet evaporation on an engineered aluminum surface is developed. Experimental study is carried out for the validation of code. The data obtained from the simulation is validated against the data obtained from an experimental study as well as the data available in the literature and good agreement was found among them. Post-validation, the effect of surface wettability and environment conditions on a droplet evaporation rate is estimated. It is inferred from the outcomes that the temperature at the apex of the drop varies linearly with the increasing relative humidity. Droplet volume has a significant impact on the evaporation rate and comparatively higher evaporative flux for a smaller volume of the drop with large contact angles. This unveils the possibility of achieving the required evaporation rate by controlling surface wettability and relative humidity conditions near the drop.

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Effects of Oxygen Element and Oxygen-Containing Functional Groups on Surface Wettability of Coal Dust with Various Metamorphic Degrees Based on XPS Experiment

Journal of Analytical Methods in Chemistry ◽

10.1155/2015/467242 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 23

Author(s):

Gang Zhou ◽

Cuicui Xu ◽

Weimin Cheng ◽

Qi Zhang ◽

Wen Nie

Keyword(s):

Functional Groups ◽

Photoelectron Spectroscopy ◽

Coal Dust ◽

Surface Wettability ◽

Polar Group ◽

Surface Oxygen ◽

Coal Surface ◽

Measurement Results ◽

The Difference ◽

Content Of Oxygen

To investigate the difference of surface oxygen element and oxygen-containing functional groups among coal dusts with different metamorphic degrees and their influence on surface wettability, a series of X-ray photoelectron spectroscopy experiments on 6 coal samples are carried out. The result demonstrates that the O/C ratio of coal surface shows an overall increasing trend compared with the result of its elements analysis. As the metamorphic degree increases, the O/C ratio on the surface gradually declines and the hydrophilic groups tend to fall off from coal surface. It could be found that different coals show different surface distributions of carboxyl and hydroxyl which are considered as the greatest promoter to the wettability of coal surface. With the change of metamorphic degree, the distribution of ether group is irregular while the carbonyl distribution keeps stable. In general, as the metamorphic degree goes higher, the content of oxygen-containing polar group tends to reduce. According to the measurement results, the contact angle is negatively related to the content of oxygen element, surface oxygen, and polar groups. In addition, compared with surface oxygen content, the content of oxygen-containing polar group serves as a more reasonable indicator of coal dust wettability.

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An experimental study of surface wettability effects on dynamic ice accretion process over an UAS propeller model

Aerospace Science and Technology ◽

10.1016/j.ast.2017.12.003 ◽

2018 ◽

Vol 73 ◽

pp. 164-172 ◽

Cited By ~ 26

Author(s):

Yang Liu ◽

Linkai Li ◽

Haixing Li ◽

Hui Hu

Keyword(s):

Experimental Study ◽

Surface Wettability ◽

Ice Accretion ◽

Accretion Process

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Experimental Study on Contact Angle of Water Droplet in High-Temperature Condition

Volume 4: Computational Fluid Dynamics, Neutronics Methods and Coupled Codes; Student Paper Competition ◽

10.1115/icone14-89614 ◽

2006 ◽

Cited By ~ 7

Author(s):

Yoshinori Hirose ◽

Tsukasa Hayashi ◽

Tatsuya Hazuku ◽

Tomoji Takamasa

Keyword(s):

Experimental Study ◽

High Temperature ◽

Water Droplet ◽

Contact Angles ◽

Point Of View ◽

Surface Wettability ◽

Atmospheric Gases ◽

Two Phase ◽

Test Plate ◽

High Temperature Condition

In recent decades, a number of reports have pointed out the importance of the influence of wall wettability on gas-liquid two-phase flow with a gas-liquid or liquid-gas phase change. However, very limited experimental data can be obtained about the wall surface wettability in BWRs high-temperature condition, or in the range from 250 to 300°C. From this point of view, we conducted an experimental study of surface wettability of droplet using a pressure vessel, we measured contact angles of water droplet under various ambient pressures (7.7, 14 and 15 MPa), atmospheric gases (nitrogen and argon), and test plate materials (aluminum, stainless 304, Zircaloy). In addition, experimental correlation was derived based on energy balance. The data obtained in this study will provide more accurate assessment of heat transfer in subchannels of BWRs.

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