RESUMO
Nanofluids receive recognition from researchers and scientists because of their high thermal transfer rates. They have impactful industrial and technological modules in daily activities. In recent times, the heat transfer rate has been strengthened even more by a certain type of nanofluid known as "carbon nanotubes". The water-based magnetohydrodynamic flow with the nanoparticles MWCNT and SWCNT over an axially rotating stretching disk is highlighted in this article. In addition, the perspectives of viscous dissipation and MHD were taken into consideration. In order to formulate the physical problem, Xue's model is considered with the thermophysical properties and characteristics of carbon nanofluid. The current modeled system of partial differential equations is transformed into an ordinary differential equation system by the suggesting of the best similarity technique. Later, the transformed system of ordinary differential equations is solved numerically by using the Keller box method and the shooting method. Figures and charts are used to study and elaborate the physical behavior of the key subjective flow field parameters. The saturation in the base fluid is considered in both kinds of carbon nanotubes, the single-wall (SWCNTs) and the multiwall (MWCNTs). It is noted that the heat transfer mechanism shows some delaying behavior due to the increase in the Eckert number and the volume fraction elevation values. For the larger volume fraction values and the magnetic parameter, the skin friction increases. In addition, while the temperature profile increases with the Biot numbers, it falls for the increasing values of the Prandtl number. Furthermore, it is noted that the irreversibility of the thermal energy is influenced by the Biot number, temperature difference, Brinkmann number, and magnetic field, which all have dynamic effects on the entropy and the Bejan number.
RESUMO
BACKGROUND: The phenomenon of rotating disks involving flows serves as a crucial element in the field of fluid mechanics. Owing to its massive practical importance in engineering and industry, considerable attention is being paid to the extension of the problems associated with rotating stretching disks. In this regard, Carbon Nanotubes (CNT) are chosen as the best example of true nano technology. CNTs have an incredible range of applications due to their extraordinary characteristics. But single rotating-stretching disk with CNTs fluid flow has not been plowed yet. OBJECTIVE: The objective of this work is to outstretch the study of viscous fluid with Carbon Nanotubes (CNTs) and transfer of heat due to radially stretching and rotating disk contingent to Navier slip, nonlinear radiations and convective boundary conditions. METHODS: Cylindrical coordinates are utilized in the modeling and the mathematical formulation of the flow equations. These flow equations take the form of ordinary differential equations by means of similarity transformations. The emanated equations are solved by two numerical methods i.e. the shooting method and the Keller box method respectively. Xue model of carbon nanotubes is incorporated to carry out the research. RESULTS: The acquired solutions are tabulated and precise values of the physical parameters with excellent matching results are shown. These results are juxtaposed with CNTs of multi-wall and single-wall carbon nanotubes, while water is taken as a base fluid. CONCLUSION: Results reveal a significant depletion in skin friction with an increase in the slip parameter. Slip, nonlinear radiation and Biot number proved as liable factors in escalating the rate of heat transfer.
