Boundary Layer Flow and Heat Transfer of Al₂O₃-TiO₂/Water Hybrid Nanofluid over a Permeable Moving Plate

• Main Authors: Nur Adilah Liyana Aladdin, Norfifah Bachok
• Format: Article
• Language: English
• Published: MDPI AG 2020-06-01
• Series: Symmetry
• Subjects: Hybrid Nanofluid; Moving Plate; Suction; Duality; Stability Analysis
• Online Access: https://www.mdpi.com/2073-8994/12/7/1064

Hybrid nanofluid is considered a new type of nanofluid and is further used to increase the heat transfer efficiency. This paper explores the two-dimensional steady axisymmetric boundary layer which contains water (base fluid) and two different nanoparticles to form a hybrid nanofluid over a permeable moving plate. The plate is suspected to move to the free stream in the similar or opposite direction. Similarity transformation is introduced in order to convert the nonlinear partial differential equation of the governing equation into a system of ordinary differential equations (ODEs). Then, the ODEs are solved using bvp4c in MATLAB 2019a software. The mathematical hybrid nanofluid and boundary conditions under the effect of suction, <i>S</i>, and the concentration of nanoparticles, ϕ1 (Al₂O₃) and ϕ2 (TiO₂) are taken into account. Numerical results are graphically described for the skin friction coefficient, Cf, and local Nusselt number, Nux, as well as velocity and temperature profiles. The results showed that duality occurs when the plate and the free stream travel in the opposite direction. The range of dual solutions expand widely for <i>S </i>and closely reduce for ϕ. Thus, a stability analysis is performed. The first solution is stable and realizable compared to the second solution. The Cf and Nux increase with the increment of <i>S</i>. It is also noted that the increase of ϕ2 leads to an increase in Cf and decrease in Nux.