A study on the freezing of nanofluid droplets using hale-shaw cell
Date of Issue2017-12-21
School of Mechanical and Aerospace Engineering
Nanofluids are colloidal suspensions of nano sized particles in a base fluid. Their property of improving the efficiency of thermal conductivity and atypical behaviour has attracted significant attention. Recent studies have also shown that the freezing formation of nanofluids differs from that of conventional fluids. Driven by motivation of learning this unusual behaviours, this experimental study seek to further gain knowledge of the freezing characteristics of nanofluids and relate the freezing geometry of impurities using titanium oxide (TiO2) as a replacement of regular impurities due to its uniform spherical shape. The analysis of the experiment was conducted using a Hele-Shaw device which enables an approximation of a two dimensional freezing formation, hence, greatly reducing the complexity in studying the shape and interfacial boundary layer. The experiments were conducted for comparing 40 nm, anatase, TiO2 nanofluid with conventional fluids using surfactants for promoting particle dispersion stability and the prevention of particle agglomeration. The effect of surfactant was firstly studied and found to have no significant effect on the freezing characteristics. However, substantial differences were observed when TiO2 nanoparticles were added. The growth of a floret formation freezing tip with increasing concentration concluded that a small concentration of titanium oxide is sufficient to create a substantial geometrical change in the freezing formation of a droplet. Nano scale geometrical elements could potentially be useful in areas such as surface coatings and 3D printing technology and for probing the quality of water.
Final Year Project (FYP)
Nanyang Technological University