Stagnation point flow of a second-grade hybrid nanofluid induced by a Riga plate

Abstract

Purpose This paper aims to accentuate the behavior of second-grade hybrid Al2O3–Cu nanofluid flow and its thermal characteristics driven by a stretching/shrinking Riga plate. Design/methodology/approach The second-grade fluid is considered with the combination of Cu and Al2O3 nanoparticles. Three base fluids namely water, ethylene glycol (EG) and methanol with different Prandtl number are also examined. The formulation of the mathematical model of second-grade hybrid nanofluid complies with the boundary layer approximations. The complexity of the governing model is reduced into a simpler differential equations using the similarity transformation. The bvp4c solver is fully used to solve the reduced equations. The observation of multiple solutions is conducted for the assisting (stretching) and opposing (shrinking) cases. Findings The impact of suction parameter, second-grade parameter, electromagnetohydrodynamics (EMHD) parameter, velocity ratio parameter and the volumetric concentration of the alumina and copper nanoparticles are numerically analyzed on the velocity and temperature profiles, skin friction coefficient and local Nusselt number (thermal rate) of the second-grade Al2O3–Cu/water. The solution is unique when (static and stretching cases) while dual for a specific range of negative in the presence of suction effect. Based on the appearance of the first solution in all cases of, it is physically showed that the first solution is stable. Further examination reveals that the EMHD and suction parameters are the contributing factors for the thermal enhancement of this non-Newtonian working fluid. Meanwhile, the viscosity of the non-Newtonian fluid also plays a significant role in the fluid motion and heat transfer rate based on the finding that the EG base fluid produces the maximum heat transfer rate but the lowest critical value and skin friction coefficient. Originality/value The results are novel and contribute to the discovery of the hybrid nanoparticles’ performance in the non-Newtonian second-grade fluid. Besides, this study is beneficial to the researchers in this field and general audience from industries regarding the factors, which contributing to the thermal enhancement of the working fluid.

Homogeneous-Heterogeneous Reactions on Al2O3-Cu Hybrid Nanofluid Flow Over a Shrinking Sheet

“…The experimental works involving the hybrid nanofluids were done [16,17]. On the other hand, the numerical studies on the hybrid nanofluids flow were done by Takabi and Salehi [18], Khashi'ie et al, [19,20], Khan et al, [21], Albeshri et al, [22], Asghar and Ying [23], among others. Moreover, the dual solutions of the hybrid nanofluid flow were examined by Waini et al, [24][25][26].…”

Carboxymethyl Cellulose Based Second Grade Nanofluid around a Horizontal Circular Cylinder

“…The coordinates of the cylinder surface, and are measured starting from the lower stagnation point and at right angle to it, respectively. The equations that represent the fluid flow are [30,31]:…”

The Impact of Thermal Radiation on Maxwell Hybrid Nanofluids in the Stagnation Region

“…In another study, Takabi and Shokouhmand [ 30 ] concluded that using hybrid nanofluids enhances the heat transfer rate as compared to pure water and nanofluids, but it has a negative effect on the friction factor and appears to be significantly offset by the pressure drop loss. Nowadays, a significant number of studies on hybrid nanofluids have been published by past scholars, including Zainal et al [ 31 ], Khashi’ie et al [ 32 ], Waini et al [ 33 ], and Algehyne et al [ 34 ].…”