Pool Boiling of Nanofluids on Biphilic Surfaces: An Experimental and Numerical Study

Area of Science:

• Surface science and nanotechnology
• Heat transfer and thermodynamics

Background:

• Enhancing pool-boiling heat transfer is crucial for thermal management in various applications.
• Surface modification and nanofluids are explored as methods to improve heat transfer efficiency.

Purpose of the Study:

• To investigate the combined effect of customized surface modification (biphilic patterns) and nanofluids on pool-boiling heat transfer.
• To evaluate the influence of nanoparticle type and concentration on bubble dynamics and heat transfer performance.

Main Methods:

• Fabrication of hydrophilic surfaces patterned with superhydrophobic regions.
• Utilized various nanofluids (water with gold, silver, aluminum, alumina nanoparticles).
• Synchronized high-speed imaging and thermography for qualitative and quantitative analysis.
• Implementation of a numerical model to study single bubble nucleation and dynamics.

Main Results:

• Biphilic patterns with optimized spacing between superhydrophobic regions demonstrated significant heat transfer enhancement.
• Controlled bubble coalescence on biphilic surfaces promoted fluid convection and surface cooling.
• Nanofluids showed a minor role in heat transfer enhancement at low concentrations (e.g., 0.1-1 wt%).
• Numerical model results correlated well with experimental observations of bubble detachment and temperature fields.

Conclusions:

• Customized biphilic surface patterns are highly effective in enhancing pool-boiling heat transfer.
• The geometry of surface patterns plays a more critical role than nanofluid concentration at low concentrations.
• Biphilic surfaces offer a promising strategy for advanced thermal management systems.