An investigation of evaporation from single saline water droplets: experimental and theoretical approaches
Paper
Sadafi, M.H., Jahn, I., Stilgoe, A.B. and Hooman, K.. 2014. "An investigation of evaporation from single saline water droplets: experimental and theoretical approaches." 19th Australasian Fluid Mechanics Conference (AFMC 2014). Melbourne, Australia 08 - 11 Dec 2014 Australia.
| Paper/Presentation Title | An investigation of evaporation from single saline water droplets: experimental and theoretical approaches |
|---|---|
| Presentation Type | Paper |
| Authors | Sadafi, M.H., Jahn, I., Stilgoe, A.B. and Hooman, K. |
| Journal or Proceedings Title | Proceedings of the 19th Australasian Fluid Mechanics Conference (AFMC 2014) |
| Number of Pages | 4 |
| Year | 2014 |
| Place of Publication | Australia |
| ISBN | 9780646596952 |
| Web Address (URL) of Paper | https://www.afms.org.au/proceedings/19/Sadafi_et_al_2014.pdf |
| Web Address (URL) of Conference Proceedings | https://www.afms.org.au/proceedings/19.html |
| Conference/Event | 19th Australasian Fluid Mechanics Conference (AFMC 2014) |
| Event Details | 19th Australasian Fluid Mechanics Conference (AFMC 2014) Parent Australasian Fluid Mechanics Conference Delivery In person Event Date 08 to end of 11 Dec 2014 Event Location Melbourne, Australia Event Venue Royal Melbourne Institute of Technology Event Web Address (URL) |
| Abstract | Heat transfer to and mass transfer from NaCl-water droplets are investigated both numerically and experimentally. A new model is presented and used to simulate saline water droplet evaporation. The model is robust enough to be applied for various initial concentrations and conditions of the droplet, ambient conditions, and dissolved media properties. The model is validated using experimental data obtained in this study on top of those already available in the literature. The experimental apparatus as well as the processing routines to optically measure droplet evaporation at a range of ambient conditions are presented. Data were collected for droplets with an initial radius of 500 µm at three temperatures 25 oC, 35 oC, and 45 oC and three air velocities 0.5 m/s, 1.5 m/s, and 2.5 m/s to provide a comprehensive validation dataset. Based on experimental and simulation data, a correlation is presented that captures the start time of solid formation. This time plays an important role in cooling tower design as it shows the time that the outer surface of the droplet dries. Using the validated model, it is shown that for 500 µm radius droplets with 5% initial mass concentration the start time of reaching the final size is 24.9% less than evaporation time of a pure water droplet. Also, the net energy required to evaporate the droplet falls by 12.2%compared to a pure water droplet. Using saline water in spray-cooling has two major effects: the energy extracted from the air per unit droplet volume is reduced (which can be compensated for by increasing the liquid flow rate). Moreover, compared to the time taken for the evaporation of a pure water droplet, the period with wet surface is shorter as a result of crust formation around the saline water droplet. This allows a shorter distance between spray nozzles and heat exchangers. |
| Contains Sensitive Content | Does not contain sensitive content |
| ANZSRC Field of Research 2020 | 4012. Fluid mechanics and thermal engineering |
| Public Notes | Files associated with this item cannot be displayed due to copyright restrictions, but may be accessed online. Please see the link in the URL field. |
| Byline Affiliations | University of Queensland |
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