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In this work, an inspection of the entropy generation of ternary nanofluids inside an irregular peristaltic channel resulting from heat transfer and fluid viscosity in addition to the combined effects of electric and magnetic fields is conducted. The flow is supposed to be subject to a combination of external forces such as an electric field, a magnetic field, thermal radiation, and Joule heating due to the Lorentz force. This model is a representation of the heat transfer processes of heat exchangers and some types of solar cells. Variation in channel width is an effective factor that has not been addressed by many researchers before, these assumptions are simulated by a set of nonlinear partial differential equations due to the dual effect of electric and magnetic forces and under the influence of special boundary conditions. This set of equations has been converted to non‐dimensional equations and then solved analytically to study the behavior of velocities, heat transfer, and the rate of entropy generation inside the channel under the influence of important embedded parameters. Some notable results have been reached, such as a clear growth of the entropy generation system by using more than one type of nanoparticle as a result of the improvement that occurs in the thermal and magnetic conductivity of the fluid, in addition to the increase in viscosity. The irreversibility resulting from friction and the electric and magnetic fields clearly rises in the middle and diminishes at the walls compared to the irreversibility resulting from thermal transfer. [ABSTRACT FROM AUTHOR]

The study of the boundary layer is considered one of the most important theories in the field of heat and mass transfer because of its important explanation that shows us the behavior of different surfaces while they are under the influence of the flow accompanied by different thermal forces. The study of corrugated surfaces is one of the engineering applications, such as flow in heat exchangers or solar cells or cooling processes during surface heat treatments. This model is also used in medical applications such as flow in arteries or movement in the intestines. So, the work deals with investigating the boundary layer surrounding a three‐dimensional sinusoidal pipe; the boundary layer was assumed to be filled with a hybrid nanofluid consisting of water +Cu nanoparticles as the main fluid, supported by a small concentration of Al2O3 or Ag nanoparticles. The boundary layer is described by a set of nonlinear partial differential equations due to the continuity, momentum, and energy equations, which are transformed into a set of dependently coupled nonlinear ordinary differential equations. The obtained system of equations was solved using numerical techniques. The behavior of the boundary layer under the varying types and concentrations of nanoparticles and the influence of the magnetic field has been depicted by a set of graphs and tables. With reference to some results, it is found that using 5% of nanoparticles of aluminum oxide raises the rate of cooling by 8% and using 5% of silver nanoparticles increases it by 5%. [ABSTRACT FROM AUTHOR]

A numerical investigation has been done to study the impact of nonlinear magnetic field, nonlinear thermal radiation, variable thickness, and Brownian motion on flow and heat transfer characteristics (i.e., skin friction and surface heat flux) as a physical application. Moreover, the impact of these forces on the rate of cooling and the mechanical properties (i.e., hardness, ductility, ...) of a surface that is cooled using nanofluid as a coolant is explored. The governing boundary layer equations describing the problem are transformed to ordinary differential equations using the similarity transformation method and are then solved numerically using the fourth-order Runge-Kutta method with shooting technique with the assistance of Mathematica program. Key words: nanofluids, variable thickness, nonlinear thermal radiation, magnetic field. Nous presentons une etude numerique de l'impact d'un champ magnetique non lineaire, de la radiation thermique non lineaire, de l'epaisseur variable et du mouvement brownien sur les caracteristiques d'ecoulement et de transfert de chaleur (i.e. le frottement superficiel et le flux de chaleur de surface) en tant que un systeme physique. Nous etudions aussi l'impact de ces forces sur le taux de refroidissement et les proprietes mecaniques (i.e., la durete, la ductilite, ...) des surfaces refroidies en utilisant un nanofluide comme refroidisseur. Les equations directrices de la couche limite sont transformees en en equations differentielles ordinaires par la methode des transformations de similarite, qui sont ensuite solutionnees par methode de Runge-Kutta du quatrieme ordre avec une technique de tir en utilisant un programme de Mathematica. [Traduit par la Redaction] Mots-cles: nanofluide, epaisseur variable, radiation thermique non lineaire, champ magnetique., 1. Introduction Study of boundary layer behavior over a moving surface is an important problem because of its importance to industry processes, such as paper production, plastic extrusion, and fibers. [...]

In order to inspect the interior of hollow organs or cavities in the human body, endoscopes are frequently employed in medicine. Over time, they have undergone substantial evolution and are now able to offer invaluable diagnostic data. The non‐invasive identification of tissue abnormalities with subcellular resolution or real‐time biochemical information is made possible by novel endoscopic optical diagnostic methods. These methods provide benefits in terms of detection, characterization, and confirmation while challenging conventional histology. An investigation is conducted on a magnetized ternary nanofluid to analyze its heat production characteristics in a heated flow scenario between two curved conduits that are peristaltic and experience sinusoidal fluctuations. In this study, the use of a new peristaltic endoscope inside a curved conduit is examined, with a specific focus on evaluating the flowing behavior and heat transference attributes. The use of a versatile and innovative endoscope equipped with peristaltic locomotion proves to be a superior approach for conducting endoscopic procedures on intricate mechanical systems. Furthermore, this advanced endoscope offers enhanced comfort for patients undertaking endoscopy of various human parts. A detailed mathematical model has been constructed to fully assess the flowing and heat transference study of this innovative endoscope using the main unsteady regulating formulas like impetus, Maxwell, and heat in their general form, then transformed to a non‐dimensional system with the assumption of a low Reynold's number and wavelength. Mathematica software was used to conduct precise and methodical calculations, enabling the acquisition of both accurate mathematical results and graphical representations. According to certain findings, the conduit is more influenced by the magnetized force, and the pressure rate over the channel width changes from a linear relationship to a sharp curve that ends in a small peak. Additionally, when utilizing different kinds of nanoparticles, there is a noticeable increase in the pressure gradient's magnitude. [ABSTRACT FROM AUTHOR]

The effect of variable thermal conductivity on the characteristics of heat transfer and mechanical properties of a moving surface on a Casson nanofluid flow as a coolant has been studied in this paper. We used similarity transformation method to transform the equations of the governing boundary-layer into ODE which are solved numerically using a mix of fourth order Runge-Kutta method and find root technique. Different values relevant parameters have been studied on the features of velocity, temperature, and the profiles of concentration and discussed in details for different values of various parameter as shape parameter, heat source parameter, radiation parameter, and magnetic parameter. The results were compared with previous published researches and obtained it in a good agreement and the results were tabulated. Furthermore, Nusselt number, Sherwood number, and the skin friction values with different parameters were calculated and the influence of theses physical quantities on the mechanical properties on the surface are analyzed and discussed in details. [ABSTRACT FROM AUTHOR]

This paper investigates the squeezing action of hybridized nanofluid flow that takes place in the mechanism of truck brakes, dampers, polymer manufacturing, power transportation, oiling structure, and food production. The modeling technique relied on a set of partial differential equations to direct the fluid, taking into consideration external factors like the magnetized force and the time-dependent source of heat and thermal radiation. The hybridized nanofluid consists of copper and aluminum oxide nanoparticles that are dispersed in the machine oil. Entropic thermodynamic analysis is also examined to evaluate its role in the thermal examination of the system. The optimal homotopy asymptotic and Adomian decomposition methods were used to solve the problem. The study examined the changes in the rate of entropy formation and the characteristics of fluid velocities, heat transference rate, and performance based on the kind and concentration of nanoparticles and external thermal impacts. The results are presented in many key components, including a notable 30% increase in heat conductivity when using a combination of nanoparticles. The use of hybridized nanofluids manages to reduce surface frictional force, whereas the employment of a combination of particles results in an increase in friction owing to the heightened viscosity of the mixture. [ABSTRACT FROM AUTHOR]

The present work provides an analysis of the hydromagnetic nanofluid boundary-layer flow over a rotating disk in a porous medium with a constant velocity in the presence of hall current and thermal radiation. The governing PDE system that describes the problem is converted to a system of ODE by the similarity transformation method, which solved analytically using optimal homotopy asymptotic method. The velocity profiles and temperature profiles of the boundary-layer are plotted and investigated in details. Moreover, the surface skin friction, rate of heat transfer are deduced and explained in details. [ABSTRACT FROM AUTHOR]

The effect of thermal radiation, heat generation, suction/injection, nanoparticles type, and nanoparticle volume fraction on heat transfer characteristics and the mechanical properties of unsteady moving cylinder embedded into cooling medium consist of water with Cu, Ag, or Al2O3 particles are studied. The governing time dependent boundary layer equations are transformed to ordinary differential equations containing unsteadiness parameter, thermal radiation parameter, heat source parameter, suction/injection parameter, curvature parameter, nanoparticle volume fraction, and Prandtl number. These equations are solved numerically. The velocity and temperature profiles within the boundary layer are plotted and discussed in details for various values of the different parameters. Also the effects of the cooling medium and the external thermal forces on the mechanical properties of the cylinder are investigated. [ABSTRACT FROM AUTHOR]

One of the most cutting-edge ways to combat cancerous cells is to use cell drug carriers. These microorganisms swarm affected cells, preventing them from spreading throughout the body when they come into contact with outside stimuli. This work proposes a new type of non-Newtonian fluid flow through microvessel contains oxytactic motile microorganisms beside nanoparticles. These microorganisms swim up the oxygen concentration gradient, they also are oxygen consumers. These microorganisms serve as drug carriers to attack and destroy hypoxic tumor cells. The movement of these items within a porous peristaltic conduit that a fluid supported by nanoparticles travels through is represented mathematically in this work. The mathematical model accounts for the impact of thermal radiation forces, thermophoresis force, and Brownian motion using the main governing equations describing this issue such as momentum, heat, concentration, microorganisms, and oxytactic microorganisms transportation, which are solved using the Adomian decomposition method. The findings concentrated on demonstrating the thermal and streamlined distribution behavior of the flow in the presence of microorganisms. These results were demonstrated through a series of graphs followed by analysis in detail. In summary, some important results were discovered from the physical analysis, such as an increase in effective thermal diffusivity while resisting the diffusivity of oxytactic microorganisms, which decays the microorganism’s dispersion. Furthermore, the non-Newtonian Sutterby parameter causes a temperature decrease in all conduit domains because it opposes fluid motion. This study is expected to offer further possibilities for enhancing drug-carrier applications in hypoxic tumor areas by gaining a better understanding of the blood flow characteristics in those places. [ABSTRACT FROM AUTHOR]

This paper inspects the combined effects of heat and mass transfers in a hybridized Williamson viscous nanofluid composed of cadmium telluride (CdTe) and silicon carbide (SiC) nanoparticles in RT42 (Rubitherm) as base fluid in the existence of heat source and thermal radiative aspects. Knowing that the base fluid RT42 is a phase change material (PCM), it is also considered that the surface on which the nanofluid flows is an expandable surface with varying thickness. The influence of chemical reactions process and viscous dissipation on the flow and temperature of the hybridized nanofluid is examined. The parameters’ influences on the problem are evaluated after setting appropriate similarity transformations to transform the collection of major partial differential equations (PDEs) into nondimensional ordinary differential equations (ODEs). The study concludes that the presence of hybridized nanoparticles of CdTe and SiC reduces the horizontal and vertical surface frictional forces of the hybrid nanofluid. The integration of nanoparticles in RT42 enhances heat transfer rates and reduces mass transfer. The thermal radiative variable declines the heat transfer of hybridized nanofluid. The results indicate that altering the variable parameter of surface thickness reduces frictional forces in both directions. [ABSTRACT FROM AUTHOR]