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The theme of this study is to investigate the theoretical and numerical simulation of heat and mass transfer of magneto hydrodynamic power-law nanofluid flow over a stretching sheet with surface heat flux and Soret/Dufour effects. The mass flux and energy flux increase with temperature and concentration differences using the Soret/Dufour impact. The similarity transformations were used to transform a physical problem into a non-linear differential equation, and the non-linear equations were solved by the Keller box technique. The Soret/Dufour and magnetic field are incorporated into a nanofluid model. The similarity transformation was used to reduce thermal energy, mass, and momentum in algebraic systems. The impact of nanofluid factors, such as generalized Brownian motion parameter Nb, Dufour parameter Df, Soret parameter Sr, Le, and Pr, are generalized Lewis and Prandtl numbers; the thermophoresis parameter Nt and magnetic parameter on dimensionless stretching surface functions are shown numerically and graphically. The quantitative relationship between heat transfer and skin friction is shown by using Keller box and MATLAB. The skin friction coefficient Cf, Sherwood number Shx, and Nusselt number Nux values were also computed and displayed on the graph. The increment in slip temperature, fluid velocity, and fluid concentration is enhanced with a high Dufour parameter. The temperature variation and fluid concentration are decreased with applied-magnetic effects because the magnetic field acts like an insulating material in heat transfer systems. The enhancement in the Nusselt number and Sherwood number is increased with Soret and Dufour effects. [ABSTRACT FROM AUTHOR]

In recent years, carbon nanotubes have been extensively explored based on numerous applications in fields such as carbon nanotube based electrodes, super capacitors, nanowires, sensors, coating with polymers, biomedical, and mechanical applications. Keeping in view the significance of carbon nanotubes in the heat transfer process in micro-electrochemical systems, this study is conducted to examine the heat transfer attributes of the carbon nanotubes using the mixture base working fluid. The focus of this investigation is to elaborate the consequence of higher chemical reactions on the bioconvective flow of carbon nanotubes. Additionally, modified Buongiorno’s nanofluid model has been used, which undertakes thermophoresis and Brownian motion effects. Heated boundary condition has also been incorporated with the migration of motile microorganisms. The hybrid nanofluid mechanism has been followed in this work. Carbon nanotubes of single-layer and multi-layer have been used simultaneously with different working fluids, such as ethylene glycol (EG) and ethylene glycol/water (EG-water). Non-dimensional flow model equations have been tackled with the bvp-4c package. The obtained outcomes have been presented for distinct profiles and tabulated data sets for the surface skin friction and heat transfer coefficient. It has been observed that when the level of Brownian motion increases, the velocity profile decreases abruptly for SWCNT-MWCNT/EG as compared to SWCNT-MWCNT/EG-water hybrid nanofluid. Opposite behavior has been seen with raising values of magnetization. High Prandtl number decrease thermal boundary layer thickness for both types of hybrid nanofluids. The motile microorganism profile expands by raising the level of bioconvective Lewis number. Moreover, the outcomes of drag force and Nusselt number have been compared, and good agreement has been found. [ABSTRACT FROM AUTHOR]

In this paper, the flow of hybrid nanofluids in a three-dimensional rectangular channel consisting of three perpendicular blocks will be analyzed in terms of heat transfer. The two perpendicular rectangular blocks are rotating with speed ω. The hybrid mixture consists of aluminum oxide and copper, and each of them will contain in volume fraction of 0.001 to 0.25. The κ - ε model of turbulent flow along with Navier and energy equation will be brought into action by using the finite element package COMSOL Multiphysics 5.6. Volume fraction and speed of rotation will be used as the parameters, and a parameter study will be done by fixing the Reynolds number Re = 50,000 with energy dissipation rate (ε) ( m 2 / s 3 ) (3.46 E − 6 to 3.76 E − 5), kinetic energy (κ) ( m 2 / s 2 ) (2.50 E − 06 to 1.23 E − 05), and the Prandtl number (0.98506 to 1.2625). It was deducted that the local Nusselt number is minimized at the outlet for stationary blocks and the maximum for the moving blocks. In addition, the mean number of Nusselt on the upper surface of the rectangular channel increases when the blocks are stationary and decreases when the blocks are moving. The study suggests that to maximize the conduction process in the channel the blocks must rotate with a certain velocity. This study also determined that with increasing the total viscosity of hybrid nanofluids, the average temperature is decreasing linearly in the middle of the channel whether the blocks are rotating or not. The temperature gradient along the z -axis decreases with increasing volume fraction only when blocks are stationary. In addition, it has been determined that the maximum average temperature occurs when the volume fractions of copper and oxide are equal to 0.001. [ABSTRACT FROM AUTHOR]