Convective transport characteristics of condensing droplets in moist air flow
(2023) In Physics of Fluids 35(2).- Abstract
Condensation of convective moist air flow is a crucial physical process and is directly related to various industries. It is essential to understand the underlying growth mechanism of condensing droplets, while past studies have commonly considered convective transport with a negligible/simplified approach. In this work, a three-dimensional transient multiphysics coupling model was developed to investigate the transport characteristics of condensing droplets in convective moist air flow. This model typically interconnects heat transfer with vapor-liquid phase change, mass transport, and fluid flow. The results reveal that convective flow significantly dominates heat and mass transport during condensation. On the gas side, the incoming... (More)
Condensation of convective moist air flow is a crucial physical process and is directly related to various industries. It is essential to understand the underlying growth mechanism of condensing droplets, while past studies have commonly considered convective transport with a negligible/simplified approach. In this work, a three-dimensional transient multiphysics coupling model was developed to investigate the transport characteristics of condensing droplets in convective moist air flow. This model typically interconnects heat transfer with vapor-liquid phase change, mass transport, and fluid flow. The results reveal that convective flow significantly dominates heat and mass transport during condensation. On the gas side, the incoming flow thins the diffusion layer at the windward part with a large concentration gradient. However, a low vapor-concentration zone behind the droplet is formed due to the resulting rear-side vortex, which presents an increased influence as the contact angle increases. By forcing molecular diffusion with convection transport, vapor transport from surroundings to the condensing interface is enhanced several times depending on the Reynolds number. Within the droplet, the flow shearing at the interface is principally responsible for the strong internal convection, while the Marangoni effect is negligible. The internal flow greatly affects the droplet temperature profile with a large gradient close to the base. Finally, convective flow contributes to over 3.3 times higher overall heat transfer coefficient than the quiescent environment. In addition, in interaction-governed growth, transport characteristics depend on not only the size and space distributions of droplets but also the interaction between droplets and convective flow.
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- author
- Wu, Zi Yi ; Yang, Li Tao ; Zheng, Shao Fei ; Gao, Shu Rong ; Yang, Yan Ru ; Gao, Tian ; Sunden, Bengt LU and Wang, Xiao Dong
- organization
- publishing date
- 2023-02-01
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physics of Fluids
- volume
- 35
- issue
- 2
- article number
- 027111
- publisher
- American Institute of Physics (AIP)
- external identifiers
-
- scopus:85147799402
- ISSN
- 1070-6631
- DOI
- 10.1063/5.0134579
- language
- English
- LU publication?
- yes
- id
- db72b1a3-652f-4c1b-b507-d682b123562f
- date added to LUP
- 2023-02-21 12:52:33
- date last changed
- 2023-11-21 09:20:54
@article{db72b1a3-652f-4c1b-b507-d682b123562f,
abstract = {{<p>Condensation of convective moist air flow is a crucial physical process and is directly related to various industries. It is essential to understand the underlying growth mechanism of condensing droplets, while past studies have commonly considered convective transport with a negligible/simplified approach. In this work, a three-dimensional transient multiphysics coupling model was developed to investigate the transport characteristics of condensing droplets in convective moist air flow. This model typically interconnects heat transfer with vapor-liquid phase change, mass transport, and fluid flow. The results reveal that convective flow significantly dominates heat and mass transport during condensation. On the gas side, the incoming flow thins the diffusion layer at the windward part with a large concentration gradient. However, a low vapor-concentration zone behind the droplet is formed due to the resulting rear-side vortex, which presents an increased influence as the contact angle increases. By forcing molecular diffusion with convection transport, vapor transport from surroundings to the condensing interface is enhanced several times depending on the Reynolds number. Within the droplet, the flow shearing at the interface is principally responsible for the strong internal convection, while the Marangoni effect is negligible. The internal flow greatly affects the droplet temperature profile with a large gradient close to the base. Finally, convective flow contributes to over 3.3 times higher overall heat transfer coefficient than the quiescent environment. In addition, in interaction-governed growth, transport characteristics depend on not only the size and space distributions of droplets but also the interaction between droplets and convective flow.</p>}},
author = {{Wu, Zi Yi and Yang, Li Tao and Zheng, Shao Fei and Gao, Shu Rong and Yang, Yan Ru and Gao, Tian and Sunden, Bengt and Wang, Xiao Dong}},
issn = {{1070-6631}},
language = {{eng}},
month = {{02}},
number = {{2}},
publisher = {{American Institute of Physics (AIP)}},
series = {{Physics of Fluids}},
title = {{Convective transport characteristics of condensing droplets in moist air flow}},
url = {{http://dx.doi.org/10.1063/5.0134579}},
doi = {{10.1063/5.0134579}},
volume = {{35}},
year = {{2023}},
}