Effect of SiO₂ nanoparticle addition on the evaporation of a suspended water droplet

The addition of nanoparticles to liquids is used in many technological processes; however, to expand the field of application of nanoparticles, it is necessary to study the evaporation of nanofluids in more detail. This paper presents an experimental investigation of heat and mass transfer during the evaporation of suspended SiO₂ nanofluid droplets. The results of the study show that the evaporation rate curve of the droplets follows the d² law, but has several slopes, unlike that of the base fluid. The mechanism of SiO₂ nanofluid droplet evaporation was presented. It is shown that nanoparticles gradually accumulate near the water–air interface and thereby affect the evaporation process. Thus, even a small fraction of particles in the evaporated layer is sufficient to cover the surface and reduce the evaporation efficiency. These results can be used to develop more efficient heat transfer media.