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The present investigation addressed the entropy generation, fluid flow, and heat transfer regarding Cu-Al 2 O 3 -water hybrid nanofluids into a complex shape enclosure containing a hot-half partition were addressed. The sidewalls of the enclosure are made of wavy walls including cold isothermal temperature while the upper and lower surfaces remain insulated. The governing equations toward conservation of mass, momentum, and energy were introduced into the form of partial differential equations. The second law of thermodynamic was written for the friction and thermal entropy productions as a function of velocity and temperatures. The governing equations occurred molded into a non-dimensional pattern and explained through the finite element method. Outcomes were investigated for Cu-water, Al 2 O 3 -water, and Cu-Al 2 O 3 -water nanofluids to address the effect of using composite nanoparticles toward the flow and temperature patterns and entropy generation. Findings show that using hybrid nanofluid improves the Nusselt number compared to simple nanofluids. In the case of low Rayleigh numbers, such enhancement is more evident. Changing the geometrical aspects of the cavity induces different effects toward the entropy generation and Bejan number. Generally, the global entropy generation for Cu-Al 2 O 3 -water hybrid nanofluid takes places between the entropy generation values regarding Cu-water and Al 2 O 3 -water nanofluids.

In this paper, we discussed the Cu - Al2O3/H2O (Hybrid nanofluid) flow over permeable exponentially stretching channel. The hybrid nanofluid involves two kinds of nanoparticles along with base fluid (pure water). Our research objective is to evaluate the heat transfer rate of hybrid nanofluid.The resulting system is numerically tackled via shooting method (bvp4c).The hybrid nanofluid gains larger rate of heat transfer as compared to simple nanofluid. The impact of non-dimension parameter on temperature profile, boundary layer will be analyzed for enormous values of dimensionless parameter. Also, boundary layer thickness when γ 0 (suction) will be compared. The present results with the existence literature will be compared for justification/validation.

Abstract The performance of friction drag, heat transfer rate, and mass transfer is illustrated the in boundary layer flow region via density of motile microorganisms. Magnetic dipole in presence of Curie temperature and density of motile microorganisms plays important role in stabilizing and controlling the momentum and thermal boundary layers. In this direction, the characteristics of the magnetic dipole on the suspensions of motile microorganisms in the flow of ferrofluid are incorporated. Heat flux in the suspensions of motile microorganisms and at the surface is computed via Fourier's law of heat conduction. Characteristics of sundry physical parameter on the ferrohydrodynamic, thermal energy, mass transfer, and bioconvection are computed numerically and analytically. It is depicted that an enhancement in thermal Rayleigh number results in the reduction of friction drag, thereby enhances the heat transfer rate and Sherwood number at the surface, while the local density of motile microorganisms enhance for larger values of bioconvection Lewis number. Further, it is characterized that bioconvection Rayleigh number has increasing behavior on the heat transfer in the boundary layer. Comparison with available results are found in an excellent agreement.

AbstractThe flow of hybrid nanoparticles with significant physical parameters with different base fluids in the presence of Biot number, velocity slip, and MHD effects has not been explored so far, particularly for a circular cylinder. Therefore, the current report is presented to offer a numerical solution for hybrid nanoparticles with base fluids (water and ethylene glycerol) via a circular cylinder. The physical situation is interpreted in terms of partial differential equations and is converted into ordinary differential equations after applying the similarity transformation. The results are presented in both tabular and graphical forms. The impact of physical parameters on velocity distribution is examined through graphs. The comparative results of hybrid nanoparticles for distinct base fluids as ethylene glycol and water are proposed and the hybrid nanoparticles with base fluid water seems to be greater than that of the hybrid nanoparticles with base fluid EG. The temperature profile of hybrid nanoparticles is found to be a decreasing function with growth in velocity slip parameter but an opposite trend is noted in case of nanoparticles . The skin friction and Nusselt number augmented for the increase in magnetic field, velocity slip, and nanoparticle while it shows a decreasing trend toward thermal slip parameter. For the both cases, improvement in Biot number helps enhance the heat transfer constantly.

AbstractWe considered the magnetized micro polar fluid with hybrid nanomaterial flow over a curved stretching surface. We discussed the effects of single wall carbon nanotube and multiwall carbon nanotube with base fluids (water and propylene glycol). Under the flow assumptions, we developed the mathematical model and applied the boundary layer approximations to reduce the system of partial differential equations. Further, the suitable similarity transformations are applied on the partial differential equations to make dimensionless system. The dimensionless system solved by means of numerical scheme via bvp4c shooting methods. Involving the dimensionless physical parameters effects are highlighted in the form of graphs and tables. Additionally, significant physical quantities i.e. Nusselt number, Couple stress coefficient and Skin friction coefficient are also presented and evaluated numerically. These results are more important which may use in the field of engineering and industrial.