Heat transfer analysis for a water droplet on micropost arrays is carried out while mimicking the environmental conditions. Since the micropost arrays spacing size alters the state of the hydrophilicity of the surface, the size of the micropost arrays spacing is varied and the resulting heat transfer characteristics are analyzed. Spreading rate of water droplet on the micropost arrays is considered and the adhesion force for the pinning of the water droplet on the micropost arrays is presented. Temperature and flow fields are predicted and the predictions of flow velocity inside the water droplet are validated through the particle image velocimetry (PIV). The Nusselt number variation for various sizes of the micropost arrays is obtained for two droplet volumes. It is found that reducing the solid fraction of micropost array beyond ϕs = 0.25, the Cassie and Baxter state of the surface changes to the Wenzel state; in which case, hydrophobic characteristics changes to hydrophilic characteristics for the water droplet. Heat transfer from the droplet bottom gives rise to development of the buoyancy and the Marangoni currents, which in turn generate two counter rotating circulation cells. The center of circulation cells moves further in the droplet upper part for the hydrophobic droplet case. The Nusselt number attains high values for the hydrophobic droplet at micropost array spacing size b = 10 μm and hydrophobic droplet at spacing size b = 50 μm due to fin effects of the micropost arrays.
Skip Nav Destination
Article navigation
Research-Article
Droplet Heat Transfer on Micropost Arrays With Hydrophobic and Hydrophilic Characteristics
Abdullah Al-Sharafi,
Abdullah Al-Sharafi
Department of Mechanical Engineering,
King Fahd University of
Petroleum and Minerals,
Dhahran 31261, Saudi Arabia
e-mail: alsharafi@kfupm.edu.sa
King Fahd University of
Petroleum and Minerals,
Dhahran 31261, Saudi Arabia
e-mail: alsharafi@kfupm.edu.sa
Search for other works by this author on:
Bekir S. Yilbas,
Bekir S. Yilbas
Department of Mechanical Engineering &
Centre of Excellence for Renewable Energy,
King Fahd University of
Petroleum and Minerals,
Dhahran 31261, Saudi Arabia
e-mail: bsyilbas@kfupm.edu.sa
Centre of Excellence for Renewable Energy,
King Fahd University of
Petroleum and Minerals,
Dhahran 31261, Saudi Arabia
e-mail: bsyilbas@kfupm.edu.sa
Search for other works by this author on:
Haider Ali
Haider Ali
Department of Mechanical Engineering,
King Fahd University of
Petroleum and Minerals,
Dhahran 31261, Saudi Arabia
e-mail: haiali@kfupm.edu.sa
King Fahd University of
Petroleum and Minerals,
Dhahran 31261, Saudi Arabia
e-mail: haiali@kfupm.edu.sa
Search for other works by this author on:
Abdullah Al-Sharafi
Department of Mechanical Engineering,
King Fahd University of
Petroleum and Minerals,
Dhahran 31261, Saudi Arabia
e-mail: alsharafi@kfupm.edu.sa
King Fahd University of
Petroleum and Minerals,
Dhahran 31261, Saudi Arabia
e-mail: alsharafi@kfupm.edu.sa
Bekir S. Yilbas
Department of Mechanical Engineering &
Centre of Excellence for Renewable Energy,
King Fahd University of
Petroleum and Minerals,
Dhahran 31261, Saudi Arabia
e-mail: bsyilbas@kfupm.edu.sa
Centre of Excellence for Renewable Energy,
King Fahd University of
Petroleum and Minerals,
Dhahran 31261, Saudi Arabia
e-mail: bsyilbas@kfupm.edu.sa
Haider Ali
Department of Mechanical Engineering,
King Fahd University of
Petroleum and Minerals,
Dhahran 31261, Saudi Arabia
e-mail: haiali@kfupm.edu.sa
King Fahd University of
Petroleum and Minerals,
Dhahran 31261, Saudi Arabia
e-mail: haiali@kfupm.edu.sa
1Corresponding author.
Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received April 17, 2017; final manuscript received January 3, 2018; published online April 6, 2018. Assoc. Editor: Gennady Ziskind.
J. Heat Transfer. Jul 2018, 140(7): 072402 (17 pages)
Published Online: April 6, 2018
Article history
Received:
April 17, 2017
Revised:
January 3, 2018
Citation
Al-Sharafi, A., Yilbas, B. S., and Ali, H. (April 6, 2018). "Droplet Heat Transfer on Micropost Arrays With Hydrophobic and Hydrophilic Characteristics." ASME. J. Heat Transfer. July 2018; 140(7): 072402. https://doi.org/10.1115/1.4039013
Download citation file:
Get Email Alerts
Cited By
Estimation of thermal emission from mixture of CO2 and H2O gases and fly-ash particles
J. Heat Mass Transfer
Non-Classical Heat Transfer and Recent Progress
J. Heat Mass Transfer
Related Articles
Flow Visualization of Submerged Steam Jet in Subcooled Water
J. Heat Transfer (February,2016)
Heat Transfer and Fluid Flow Characteristics in a Sessile Droplet on Oil-Impregnated Surface Under Thermal Disturbance
J. Heat Transfer (September,2017)
Flow Visualization and Stream Temperature Measurement of Liquid Hydrogen Line Chill Down Experiments
J. Heat Transfer (February,2015)
Flow Field Inside a Sessile Droplet on a Hydrophobic Surface in Relation to Self Cleaning Applications of Dust Particles
J. Heat Transfer (April,2017)
Related Proceedings Papers
Related Chapters
Numerical Simulation of Nucleate Spray Cooling: Effect of Droplet Impact on Bubble Growth and Heat Transfer in a Thin Liquid Film
Inaugural US-EU-China Thermophysics Conference-Renewable Energy 2009 (UECTC 2009 Proceedings)
Nucleation of Bubbles in Perfluoropentane Droplets Under Ultrasonic Excitation
Proceedings of the 10th International Symposium on Cavitation (CAV2018)
Completing the Picture
Air Engines: The History, Science, and Reality of the Perfect Engine