ABSTRACT
A composite model for the average heat flux using both pure fluids and nanofluids is established incorporating microlayer evaporation, transient conduction due to bubble departure, and micro-convection due to bubble growth and movement. Water is the most popular base fluid, while glycol–ethylene, oil, bio-fluids, and polymer solutions have also been used. A variety of materials are commonly used as nanoparticles, such as alumina, titania, silica, zirconia, graphite, carbon nanotubes, diamond, copper, and gold. Critical heat flux (CHF) is also an important characteristic in boiling. CHF is the end of nucleate boiling and refers to the limit of safe operation of a heat transfer system. In nuclear reactors or electrical components, loss of liquid contact with surface will dramatically decrease the heat transfer coefficient and causes damage to the surfaces. Boiling is a complex phenomenon as it involves both phase change and forced convection due to bubble movement.
