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An inclined plate is being approached by a mixed convective boundary layer nanofluid flow of titanium dioxide–water through a porous medium. A numerical analysis has been done to investigate the effects of chemical reactions on the considered nanofluid flow. With the aid of a system of governing partial differential equations, a set of nonlinear ordinary differential equations for taking into consideration nanofluid flow have been derived using appropriate matching transformations. The Runge–Kutta method, as well as the Nachtsheim and Swigert Shooting method, is applied to numerically resolve the group of subsequent nondimensionalized equations. The associated numerical result was then successfully compared with the available published literature in a few unique, limited circumstances. Based on the considered nanofluid flow characteristics for heat as well as mass transfer, the effects of the Schmidt number, the permeability, and the chemical reaction parameters of the titanium dioxide–water nanofluid flow have been examined, assessed, and presented for velocity in conjunction with the local skin friction coefficient, temperature in conjunction with the local Nusselt number, as well as concentration in conjunction with the local Sherwood number. Numerical results reveal that the local Sherwood number Sh, as well as the local Nusselt number Nux, increase, whereas the local skin friction coefficient Cf decreases due to the increase in the chemical reaction parameter Krp. [ABSTRACT FROM AUTHOR]

The growing demand for energy calls for efficient utilization of natural energy resources in developing useful work. Thermodynamic irreversibility deals with the disorderliness in any system. This work investigates the energy optimization of a cylinder experiencing stretching and rotation immersed with aluminum alloys (AA7072-AA7075) in engine oil-based nanofluid. The Maxwell nanofluid model is employed to check the thermophysical properties of nanofluids. Heat transfer occurred at the cylinder's surface by considering the constant and prescribed temperature. Forced convection is due to a stretchable rotating boundary, while natural convection is owing to a thermal gradient in the system. The dimensionless ordinary differential equations are obtained by using the appropriate ansatz and solved numerically through the bvp4c technique. A comparison profile of constant wall temperature and prescribed surface temperature shows that entropy generation and Bejan number are reduced for the former and increased for the latter, while thermal transport exhibits an opposite behavior. The axial and azimuthal wall stress parameters diminished due to an increment in Reynolds number. The heat transport rate is comparatively higher for AA7075/Engine oil than AA7072/Engine oil. [ABSTRACT FROM AUTHOR]

Non-Newtonian fluids display fascinating and versatile flow behavior, enabling applications in fields where precise control and manipulation of viscosity are required. This paper presents the rheology of Homann stagnation point flow for a Jeffrey fluid containing gyrotactic microorganisms over a biaxially stretching surface. The system of equations is solved numerically using appropriate similarity transformations and conditions. The boundary conditions are set to maintain a fixed physical environment, and the far field values are defined accordingly. The dual solutions are found and expressed in terms of relevant quantities, and their behavior is analyzed using graphical representations via bvp5c. Stability analysis is conducted as well. The model is extended to study the behavior of Jeffrey nanofluids under the influence of various physical phenomena such as thermophoresis, Brownian motion, Ohmic heating, heat source/sink, radiation, and chemical reaction. The model presented in this paper can help researchers predict and optimize the behavior of such systems for a range of industrial and biomedical applications. It is observed that when the smallest eigenvalue is positive, the disturbance initially decreases, and the flow is stable, otherwise unstable. The stretching/shrinking parameters affect the flow field and boundary layer characteristics, leading to changes in the skin friction forces and an increase in the skin friction coefficient. Moreover, the Peclet number augmented the concentration of microorganisms due to gyrotactic bioconvection for first and second solutions, whereas bioconvective Lewis number shows an opposite trend. The comparison of the present results, as a simplified case, with existing literature demonstrates good agreement. [ABSTRACT FROM AUTHOR]

Hybrid nanofluids have gained much attention due to their better stability, enhanced thermal conductivity, and physical strength. This manuscript investigates nanofluid flow, induced due to an infinite plate, which is moving (at a constant velocity) toward/receding from normal stagnation point flow. The surface of the plate is suspended and immersed with water as a base fluid and nanoparticles, namely Copper and Alumina. The flow is governed by Reynolds number (Re), which is proportional to the constant velocity of the moving plate and is an exact reduction of the Navier–Stokes equations. Moreover, Hiemenz's planar and Homann's axisymmetric flows normal to the stagnation point are considered. Heat transport analysis is carried out by using Cattaneo–Christov theory with Ohmic heating and heat source/sink effects. The governing equations are solved by bvp4c in MATLAB. The behavior of skin friction, flow, and energy distribution is perceived by variation of pertinent parameters. The numerical and asymptotic solutions are computed for the wall shear stress parameter. It is seen that the numerical solution matches its asymptotic behaviors over an intermediate range of small and large valued Reynolds number. The asymptotic values (small-Re) of wall stress reduces for plate advancing toward the stagnation-point flow and receding from the stagnation-point flow for Hiemenz and Homann flow. The increment in magnetic parameter reduced the fluid flow by generating a resistive force against it; however, the energy of the system is enhanced because of it. The augmentation of nanofluid volume fraction initiates the random motion among the nanoparticles which raises the temperature field. Thermal relaxation time parameter causes the particles to require supplementary time for the conduction of heat toward the adjacent particles, which declines the thermal transport. In general, the thermal transport is enhanced for the hybrid nanofluids rather than mono nanofluids. [ABSTRACT FROM AUTHOR]

Carbon nanotubes have garnered considerable interest from academia and industry due to their unique properties and potential applications. This study examines fluid flow induced by a plate moving at a constant velocity towards/receding from normal stagnation point flow. The plate's surface is immersed with ethylene glycol and two types of carbon nanotubes: single‐walled and multi‐walled. The Reynolds number, proportional to the plate's velocity, governs the flow. Thermal transport analysis includes Ohmic heating, heat source/sink effects for constant wall temperature and prescribed surface temperature, and entropy generation analysis. Similarity ansatz is used to obtain non‐dimensional ordinary differential equations, and numerical and asymptotic solutions are computed using MATLAB's bvp4c routine (finite difference‐based approach). By varying the relevant parameters, the study interprets the behavior of entropy generation, Bejan number, skin frictions, Nusselt number, flow, and energy profiles. The numerical solutions are observed to match their asymptotic behaviors within an intermediate range of small and large Reynolds numbers for the wall stress parameter. The magnetic parameter produces a resistive force that reduces fluid flow but enhances the system's energy. Moreover, understanding the flow and heat transfer characteristics of CNT‐based nanofluids induced by a moving plate can provide insights into the design and optimization of thermal systems, including efficient heat exchangers used in power generation, chemical, and petrochemical industries. [ABSTRACT FROM AUTHOR]

Lubrication theory has attained attention lately due to its practical applications, such as the formation of thin films, adhesives, and lubrication of components of machines. Jeffrey's nanofluid flow over the stagnation region past a power-law lubricated surface is presented in this study. Buongiorno's model is employed to scrutinize the effects of thermophoresis and Brownian motion phenomena with constant wall and prescribed surface temperature (PST) and effects of heat source/sink, chemical reaction, and Joule heating. Due to the continuity of shear stress of fluid-lubricant and velocity at the interface, interfacial conditions are generated. By similarity conversions, ordinary differential equations are obtained and their solutions are computed numerically. For power-law index equaling 1 2 , local similarity solutions are calculated by adopting a finite difference scheme, viz. bvp4c in MATLAB. The energy profiles for constant and prescribed temperatures are monitored. The effects of pertinent parameters on the flow, thermal, and mass distributions are scrutinized and illustrated in graphs. Flow field decreases significantly by raising slip parameter as the aptitude of power-law lubricant to improve the velocity of the bulk fluid. The numerical comparison of wall stress and Nusselt number is also presented. The slip and Jeffrey's material parameters raise the numerical outcomes of the wall shear stress. In addition, increment in Prandtl number enhances the numerical value of the Nusselt number; however, it reduces for relaxation-to-retardation times ratio. [ABSTRACT FROM AUTHOR]

Entropy is the measure of the amount of energy in any physical system that is not accessible for the useful work, which causes a decrease in a system's thermodynamic efficiency. The idea of entropy generation analysis plays a vital role in characterizing the evolution of thermal processes and minimizing the impending loss of available mechanical power in thermo-fluid systems from an analytical perspective. It has a wide range of applications in biological, information, and engineering systems, such as transportation, telecommunication, and rate processes. The analysis of the entropy generation of axisymmetric magnetohydrodynamic hybrid nanofluid (S i O 2 − M o S 2) /water flow induced by rotating and stretching cylinder in the presence of heat radiation, ohmic heating, and the magnetic field is focus of this study. Thermal energy transport of hybrid nanofluids is performed by applying the Maxwell model. Heat transport is carried out by using convective boundary condition. The dimensionless ordinary differential equations are acquired by similarity transformations. The numerical solution for these differential equations is obtained by the bvp4c program in MATLAB. A comparison between nanofluid and hybrid nanofluid is made for flow field, temperature, and entropy generation. Comparison of nanofluid flow with hybrid nanofluid flow exhibits a higher rate of heat transmission, while entropy generation exhibits the opposite behavior. It is observed that the flow and heat distribution increase as the solid volume fraction's value grows. An increase in entropy is indicated by augmentation in the Brinkman number and temperature ratio parameter, but the Bejan number shows a declining trend. Furthermore, outcomes of the Nusselt number for hybrid nanofluid and nanofluid are calculated for various parameters. It is noticed that the Nusselt number is reduced for enlarging the magnetic field and Eckert number. The axial and azimuthal wall stress parameters are declined by augmenting the Reynolds number. [ABSTRACT FROM AUTHOR]

Entropy is the measure of the amount of energy in any physical system that is not accessible for the useful work, which causes a decrease in a system's thermodynamic efficiency. The idea of entropy generation analysis plays a vital role in characterizing the evolution of thermal processes and minimizing the impending loss of available mechanical power in thermo-fluid systems from an analytical perspective. It has a wide range of applications in biological, information, and engineering systems, such as transportation, telecommunication, and rate processes. The analysis of the entropy generation of axisymmetric magnetohydrodynamic hybrid nanofluid (SiO2 -MoS2)/water flow induced by rotating and stretching cylinder in the presence of heat radiation, ohmic heating, and the magnetic field is focus of this study. Thermal energy transport of hybrid nanofluids is performed by applying the Maxwell model. Heat transport is carried out by using convective boundary condition. The dimensionless ordinary differential equations are acquired by similarity transformations. The numerical solution for these differential equations is obtained by the bvp4c program in MATLAB. A comparison between nanofluid and hybrid nanofluid is made for flow field, temperature, and entropy generation. Comparison of nanofluid flow with hybrid nanofluid flow exhibits a higher rate of heat transmission, while entropy generation exhibits the opposite behavior. It is observed that the flow and heat distribution increase as the solid volume fraction's value grows. An increase in entropy is indicated by augmentation in the Brinkman number and temperature ratio parameter, but the Bejan number shows a declining trend. Furthermore, outcomes of the Nusselt number for hybrid nanofluid and nanofluid are calculated for various parameters. It is noticed that the Nusselt number is reduced for enlarging the magnetic field and Eckert number. The axial and azimuthal wall stress parameters are declined by augmenting the Reynolds number. [ABSTRACT FROM AUTHOR]