Numerical Simulation and Experimental Validation of Surface Water Evaporation Reduction Using Novel Coating Fluids

Document Type : Original Article

Authors

1 M.Sc. in Chemical Engineering, Imam Hossein Comprehensive University, Tehran, Iran

2 Assistant Professor, Department of Mechanical Engineering, Jundi-Shapur University of Technology, Dezful, Iran.

3 Ph.D. in Agricultural Engineering,University of Tehran, Tehran, Iran

4 Ph. D. in Mechanical Engineering, Imam Hossein Comprehensive University, Tehran, Iran.

Abstract

Given the decline in water resources, the control and reduction of evaporation from free water surfaces in reservoirs and dams is of considerable importance. One effective method for achieving this goal is the application of anti-evaporation surface-covering fluids. In this study, the effect of the anti-evaporation fluid hexadecanol on water evaporation was investigated. In the experimental section, the reduction of surface water evaporation over a 16-day period was assessed using a Class A pan. During this period, parameters influencing evaporation namely air flow velocity, temperature, and relative humidity were measured three times per day. In the numerical section, the simulation was carried out using the finite-volume method by solving th continuity and momentum equations under the assumption of multiphase flow. The multiphase model was implemented via the Volume of Fluid (VOF) method, considering four phases: water, air, water vapor, and the anti-evaporation fluid. Simulations were performed for two conditions—with and without the anti-evaporation fluid applied to the water surface—using an initial water depth of 2. 4 cm. Following mesh-independence analysis and validation of the model with the experimental data, the unsteady simulation results were examined over a 24-minute interval. The findings indicated that the use of the covering fluid can reduce evaporation by approximately 76%. Furthermore, the discrepancy between the simulation predictions and the experimental measurements was approximately 13%, which is regarded as acceptable.

Keywords

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References

[1] M. New, M. Todd, M. Hulme, and P. Jones, "Precipitation measurements and trends in the 20th century," Int. J. Climatol. , vol. 21, no. 15, pp. 1889–1922, 2001.
[2] M. L. Roderick and G. D. Farquhar, "The cause of decreased pan evaporation over the past 50 years," Science, vol. 298, pp. 1410–1411, 2002.
[3] P. D. Jones and A. Moberg, "Hemispheric and large-scale surface air temperature variations: An extensive revision and an update to 2001," J. Climate, vol. 16, no. 2, pp. 206–223, 2003.
[4] E. Y. Yildirim, M. Turkes, and M. Tekiner, "Time series analysis of long term variations in stream flow data of some stream flow stations over the Gediz basin and in precipitation of the Akhisar station," Pakistan J. Biol. Sci. , vol. 7, pp. 17–24, 2004.
[5] S. Z. Kang, "Towards water and food security in China," Chin. J. Eco Agric. , vol. 22, pp. 880–885, 2014 (in Chinese).
[6] P. H. Gleick, "Climate change, hydrology, and water resources," Rev. Geophys. , vol. 27, no. 3, pp. 329–344, 1989.
[7] International Groundwater Resources Assessment Center, "Groundwater Stress," 2020. [Online]. Available: https: //www. un-igrac. org
[8] B. S. Limjirakan and A. Limsakul, "Trends in Thailand pan evaporation from 1970 to 2007," Atmos. Res. , vol. 108, pp.    122–127, 2012.
[9] C. W. Thornthwaite, "An approach toward a rational classification of climate," Geogr. Rev. , vol. 38, no. 1, pp. 55–94, 1948.
[10] X. Yao, H. Zhang, Ch. Lemckert, A. Brook, and P. Schouten, Evaporation reduction by suspended and floating covers: Overview, modelling and efficiency, Urban Water Security Research Alliance Technical Report, Australia, 2010.
[11] M. Coleman, Review and Discussion on the Evaporation Rate of Brines, Mundijong, 2000, pp. 1–12.
[12] H. Ali, C. A. Madramootoo, and S. Abdel Gwad, "Evaporation model of Lake Qaroun as influenced by lake salinity," Irrig. Drain. , vol. 50, pp. 9–17, 2001.
[13] G. L. Gaines, Insoluble Monolayers at Liquid-Gas Interfaces, New York: Interscience Publishers, 1966.
[14] G. T. Barnes and I. R. Gentle, Interfacial Science: An Introduction, Oxford: Oxford Univ. Press, 2005.
[15] J. Zahiri and M. Karim Zadeh, "Evaporation suppression from the water surface using monolayers," Irrigation and Water Engineering, vol. 13, no. 3, pp. 268–284, 2023.
[16] G. T. Barnes, "The potential for monolayers to reduce the evaporation of water from large water storages," Agric. Water Manag. , vol. 95, no. 4, pp. 339–353, 2008.
[17] M. A. Herzig, G. T. Barnes, and I. R. Gentle, "Improved spreading rates for monolayers applied as emulsions to reduce water evaporation," J. Colloid Interface Sci. , vol. 357, no. 1, pp. 239–242, 2011.
[18] E. L. Prime et al. , "Rational design of monolayers for improved water evaporation mitigation," Colloids Surf. A, vol. 415, pp. 47–58, 2012.
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Volume 17, Issue 1 - Serial Number 65
Serial number 65. Spring 2026
May 2026
Pages 91-101

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History

  • Receive Date: 01 August 2025
  • Revise Date: 12 November 2025
  • Accept Date: 17 December 2025
  • Publish Date: 22 May 2026

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