Investigation of Droplet Atomization and Evaporation in Solution Precursor Plasma Spray Coating
Solution precursor plasma spray (SPPS) is a novel and promising technique in producing nanostructured coatings. This technique involves complex heat, mass and momentum transfer among the liquid feedstock, droplets, plasma jet and the coating material. Nevertheless, the droplet atomization and evapor...
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2017-11-01
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doaj-9ac334bb23054e79ae6ecb114b0468902020-11-24T21:46:26ZengMDPI AGCoatings2079-64122017-11-0171120710.3390/coatings7110207coatings7110207Investigation of Droplet Atomization and Evaporation in Solution Precursor Plasma Spray CoatingHongbing Xiong0Weiqi Sun1Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Zhejiang University, Hangzhou 310027, ChinaKey Laboratory of Soft Machines and Smart Devices of Zhejiang Province, Zhejiang University, Hangzhou 310027, ChinaSolution precursor plasma spray (SPPS) is a novel and promising technique in producing nanostructured coatings. This technique involves complex heat, mass and momentum transfer among the liquid feedstock, droplets, plasma jet and the coating material. Nevertheless, the droplet atomization and evaporation in the plasma jet is one of the most essential parts to obtain the desired coating architecture. In the present work, a three-dimensional two-way-coupled Eulerian-Lagrangian code is used to simulate the interactions between the solution precursor and plasma. In order to obtain a more realistic understanding regarding droplet atomization and vaporization, the flash-boiling effect is modeled by an improved vaporization model. This model could provide accurate details for the droplet pyrolysis and help to optimize the solution precursor plasma spray process. We show that the fragmentation of the liquid stock and its vaporization mainly dominate the spraying details and can be decisive to the coating quality. We further investigate their role in SPPS and separately probe their inner link with the flow field relating to the distinctive area when droplets are flying through the thermal flow field. Our studies reveal that ethanol droplets, compared to those of water, show a superior characteristics in SPPS, owing to the low boiling point and low surface tension, conducive to the evaporation and atomization of droplets. In addition, the mixture of the plasma gas with hydrogen breaks the droplets more thoroughly compared to the pure plasma. The numerical results were compared and found to agree well with previous experimental and simulation work.https://www.mdpi.com/2079-6412/7/11/207thermal spraysalt pyrolysiscomputational fluid dynamics (CFD)discrete particle method (DPM)multiphase flow |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Hongbing Xiong Weiqi Sun |
spellingShingle |
Hongbing Xiong Weiqi Sun Investigation of Droplet Atomization and Evaporation in Solution Precursor Plasma Spray Coating Coatings thermal spray salt pyrolysis computational fluid dynamics (CFD) discrete particle method (DPM) multiphase flow |
author_facet |
Hongbing Xiong Weiqi Sun |
author_sort |
Hongbing Xiong |
title |
Investigation of Droplet Atomization and Evaporation in Solution Precursor Plasma Spray Coating |
title_short |
Investigation of Droplet Atomization and Evaporation in Solution Precursor Plasma Spray Coating |
title_full |
Investigation of Droplet Atomization and Evaporation in Solution Precursor Plasma Spray Coating |
title_fullStr |
Investigation of Droplet Atomization and Evaporation in Solution Precursor Plasma Spray Coating |
title_full_unstemmed |
Investigation of Droplet Atomization and Evaporation in Solution Precursor Plasma Spray Coating |
title_sort |
investigation of droplet atomization and evaporation in solution precursor plasma spray coating |
publisher |
MDPI AG |
series |
Coatings |
issn |
2079-6412 |
publishDate |
2017-11-01 |
description |
Solution precursor plasma spray (SPPS) is a novel and promising technique in producing nanostructured coatings. This technique involves complex heat, mass and momentum transfer among the liquid feedstock, droplets, plasma jet and the coating material. Nevertheless, the droplet atomization and evaporation in the plasma jet is one of the most essential parts to obtain the desired coating architecture. In the present work, a three-dimensional two-way-coupled Eulerian-Lagrangian code is used to simulate the interactions between the solution precursor and plasma. In order to obtain a more realistic understanding regarding droplet atomization and vaporization, the flash-boiling effect is modeled by an improved vaporization model. This model could provide accurate details for the droplet pyrolysis and help to optimize the solution precursor plasma spray process. We show that the fragmentation of the liquid stock and its vaporization mainly dominate the spraying details and can be decisive to the coating quality. We further investigate their role in SPPS and separately probe their inner link with the flow field relating to the distinctive area when droplets are flying through the thermal flow field. Our studies reveal that ethanol droplets, compared to those of water, show a superior characteristics in SPPS, owing to the low boiling point and low surface tension, conducive to the evaporation and atomization of droplets. In addition, the mixture of the plasma gas with hydrogen breaks the droplets more thoroughly compared to the pure plasma. The numerical results were compared and found to agree well with previous experimental and simulation work. |
topic |
thermal spray salt pyrolysis computational fluid dynamics (CFD) discrete particle method (DPM) multiphase flow |
url |
https://www.mdpi.com/2079-6412/7/11/207 |
work_keys_str_mv |
AT hongbingxiong investigationofdropletatomizationandevaporationinsolutionprecursorplasmaspraycoating AT weiqisun investigationofdropletatomizationandevaporationinsolutionprecursorplasmaspraycoating |
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1725902156707397632 |