Droplet Departure Characteristics and Dropwise Condensation Heat Transfer at Low Steam Pressure
| العنوان: | Droplet Departure Characteristics and Dropwise Condensation Heat Transfer at Low Steam Pressure |
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| المؤلفون: | Wei Xu, Benli Peng, Zhong Lan, Rongfu Wen, Yaqi Cheng, Xuehu Ma |
| المصدر: | Journal of Heat Transfer. 138 |
| بيانات النشر: | ASME International, 2016. |
| سنة النشر: | 2016 |
| مصطلحات موضوعية: | endocrine system, Materials science, Mechanical Engineering, Condensation, technology, industry, and agriculture, Thermodynamics, Steam pressure, 02 engineering and technology, Dissipation, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Kinetic energy, complex mixtures, 01 natural sciences, eye diseases, 010305 fluids & plasmas, Physics::Fluid Dynamics, Subcooling, Heat flux, Mechanics of Materials, 0103 physical sciences, Heat transfer, General Materials Science, Dropwise condensation, 0210 nano-technology |
| الوصف: | Dropwise condensation has received significant attention due to its great potential to enhance heat transfer by the rapid droplet removal. In this work, droplet departure characteristics on a vertical surface, especially the droplet departure retention at low steam pressure and its effect on the heat transfer performance are investigated experimentally. The energy dissipation increases during droplet movement due to the increased viscosity at low pressure. Droplet oscillation caused by excess kinetic energy weakens and the dynamic contact angle (CA) hysteresis becomes apparent, which is not beneficial to droplet departure. Condensed droplets grow larger and fall more slowly at low pressure compared to that at atmospheric pressure. The droplet moves smoothly downward once it grows to departure size at atmospheric pressure while the droplet exhibits an intermittent motion at low pressure. Based on the droplet departure characteristics, a unified heat transfer model for dropwise condensation is developed by introducing the pressure-dependent departure velocity. The modified model very well predicts heat transfer performances at various pressures and the nonlinearity of heat flux varying with surface subcooling is quantitatively explained. This work provides insights into the heat transfer mechanism of dropwise condensation and offers a new avenue to further enhance heat transfer at low steam pressure. |
| تدمد: | 1528-8943 0022-1481 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_________::84a06f96fa450de21d48a924fa124d73Test https://doi.org/10.1115/1.4032956Test |
| رقم الانضمام: | edsair.doi...........84a06f96fa450de21d48a924fa124d73 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15288943 00221481 |
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