Dynamics of water conveying iron oxide and graphene nanoparticles subject to stretching/spiraling surface: An asymptotic approach

The applications of hybrid nanofluids due to its heat transfer characteristics has piqued the interest of many researchers. Inspired by this, in this article, hybrid nanofluid flow is considered, where the fluid is flowing normally over a disk that is exhibiting rotation and linear stretching in the stagnation region. The energy transport and irreversibility analysis are conducted with Ohmic heating, thermal radiation, and heat source/sink. Homann's problem is modified with simultaneous effects of the linear radial stretchiness of the disk, uniform rotation, and magnetohydrodynamic, which contributes to the spiral motion. It is noted that the surface velocity is generated as a spiral logarithm because of rotation and linear stretching of the disk. Two types of nanoparticles are considered, i.e., ferrous oxide and graphene immersed in water. Furthermore, ordinary differential equations are generated by applying appropriate similarity ansatz. The problem is studied numerically and illustrated graphically for both hybrid nanofluid and conventional nanofluid profiles in MATLAB (bvp4c). The influence of pertinent parameters on the radial and azimuthal velocities and temperature are discussed. The comparison of asymptotic values of wall stress parameters is made, and the results obtained are in impeccable agreement with the ones mentioned in the literature. The impact of the Prandtl number is provided, which represents that the thermal transport phenomenon is a decreasing function of the Prandtl number. Entropy generation and Bejan number are magnified because of thermal radiation. Entropy generation signifies the feasibility of a reaction and how the energy is lost or degraded in a system. It is also noted that the inclusion of a hybrid nanofluid causes the thermal conductivity of the system to incline. CO 2022 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Ain Shams University. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Automated summary

The applications of hybrid nanofluids in heat transfer have attracted the attention of researchers. This article considers the flow of a hybrid nanofluid over a rotating and linearly stretching disk in the stagnation region. The effects of rotation, linear stretching, and magnetohydrodynamics are taken into account. Numerical analysis and graphical illustrations are presented for both hybrid nanofluid and conventional nanofluid profiles. The influence of various parameters on velocity and temperature distributions is discussed, as well as the impact of Prandtl number and entropy generation.