Search results

This paper aims to optimize bioconvective heat transfer for magnetohydrodynamics Eyring–Powell nanofluids containing motile microorganisms with variable viscosity and porous media in ciliated microchannels.

The flow problem is first modeled in the two-dimensional frame and then simplified under low Reynolds number and long wavelength approximations. The numerical method is used to examine the impact of thermal radiation, temperature-dependent viscosity, mixed convection, magnetic fields, Ohmic heating and porous media for velocity, temperature, concentration and motile microorganisms. Graphical results are presented to observe the impact of physical parameters on pressure rise, pressure gradient and streamlines.

It is observed that the temperature of nanofluid decreases with higher values of the viscosity parameter. It is absolutely in accordance with the physical expectation as the radiation parameter increases, the heat transfer rate at the boundary decreases. Nanoparticle concentration increases by increasing the values of bioconvection Rayleigh number. The density of motile microorganisms decreases when bioconvection Peclet number is increased. The velocity of the nanofluid decreases with higher value of Darcy number. With increase in the value of bioconvection parameter, the flow of nanofluid is increased.

The bioconvective peristaltic movement of magnetohydrodynamic nanofluid in ciliated media is proposed. The non-Newtonian behavior of the fluid is described by using an Eyring–Powell fluid model.

The complex behavior of viscoelastic fluids and its flow analysis under the impact of transverse magnetic field are becoming increasingly important in numerous emerging applications including biomedical engineering, aerospace engineering, geophysics and industrial applications. Additionally, the thermal analysis and fluid flow driven by propagating membranes will aid significant applications for microscale transport in bio-thermal systems. This study aims to investigate the thermal effects of viscoelastic fluids driven by membrane-induced propagation and transverse magnetic field.

The propagation of the membranes will work as pump which pushes the fluids from bottom to top against the gravitation force; however, there is backflow due to compression and expansion phases of membrane propagation. The Jeffrey fluid model is employed to analyze the viscoelastic fluid flow, with entropy generation examined and equations solved analytically under low Reynolds number and long-wavelength assumptions.

The findings reveal that an increase in magnetic field strength impedes fluid flow, while higher values of the Grashof number, heat source parameter and Jeffrey fluid parameter enhance fluid motion. The study’s findings have significant implications for optimizing magnetohydrodynamic systems in various emerging applications, including biomedical engineering, aerospace, geophysics and industrial processes.

This study aims to investigate the impact of a transverse magnetic field on the flow and heat transfer characteristics of viscoelastic fluids driven by membrane propagation.

Building on the value chain model, this study develops a theoretical framework to illustrate the associations between digitalization and firms’ value chain activities from three typical dimensions including R&D investment, manufacturing cost efficiency and marketing cost efficiency. The roles of unabsorbed and absorbed slack resources in their relationships are also examined.

Based upon a large sample of Chinese manufacturing firms from 2016 to 2020 and then employing text mining-based analysis and the multiple regression model, this study empirically tests the effects of digitalization on firms’ value chain activities and how these effects are moderated by slack resources.

The findings show that increase in digitalization leads to an increase in firms’ R&D investment and a decline in manufacturing cost, but results in an increase in marketing cost. In addition, the unabsorbed slack resources and absorbed slack resources play differentiated roles in the associations between digitalization and these value chain activities.

This study contributes to the debate on how digitalization facilitates or hinders the value increment by employing the value chain model and further analyzing the impacts of digitalization on three value chain dimensions: R&D investment, manufacturing cost efficiency and marketing cost efficiency. This study extends the possibility that the influences of digitalization on different value chain dimensions may vary depending on some key contingency factors such as unabsorbed and absorbed slack resources.

Surface properties (smooth or roughness) play a critical role in controlling the wettability, surface area and other physical and chemical properties like fluid flow behaviour over the rough and smooth surfaces. It is reported that rough surfaces are offering more significant insights as compared to smooth surfaces. The purpose of this study is to examine the effects of surface roughness in the diverging channel on physiological fluid flows.

A mathematical formulation based on the conservation of mass and momentum equations is developed to derive exact solutions for the physical quantities under the assumption of low Reynolds numbers and long wavelengths, which are appropriate for biological transport scenarios.

The results reveal that an increase in surface roughness reduces axial velocity and volumetric flow rate while increasing pressure distribution and turbulence in skin friction.

These findings offer valuable insights for biological flow analysis, highlighting the effects of surface roughness, non-uniformity of the channel and magnetic fields.

These findings are very much applicable for designing the pumping devices for transportation of the fluids in non-uniform channels.

This study examines the impact of surface roughness on the peristaltic pumping of viscoelastic (Jeffrey) fluids in diverging channels with transverse magnetic fields.

This study aims to explore the hydrodynamic and thermal behavior of an incompressible fluid flowing between uniformly corotating disks with finite radii. The narrow gap between the disks necessitates accounting for slip flow in the radial direction, departing from the classic no-slip model.

The author uses a perturbation approach and derives full analytical approximations to the Navier–Stokes and energy equations up to the second order. Higher-order truncations require significant numerical effort due to the complexity of the resulting expressions.

For the no-slip case, the momentum solutions perfectly match those found in the literature. The author then demonstrates the convergence of the series solutions with slip for selected specific parameter sets. Finally, the author investigates the impact of both slip and Reynolds number on the velocity field, pressure and temperature field between the inlet and outlet positions.

The key finding is that both factors lead to thinner momentum and thermal boundary layers within the corotating finite disk setup, resulting in cooler disk surfaces.

This study aims to explore the collective influence of several factors, namely, thermal radiation, Brownian motion, magnetic field and variable viscosity parameter, on the boundary layer flow, heat and mass transfer of an electrically steering nanofluid over a radially stretching exterior subjected to convective heating. In addition, the impacts of thermal and solutal buoyancy forces and activation energy are taken into account. The enlarging velocity is assumed to vary linearly with radial distance.

Through the similarity transformation technique, the governing highly nonlinear partial differential equations are transformed into a set of nonlinear ordinary differential equations, which are then numerically solved using the Runge–Kutta–Fehlberg method with a shooting technique.

Graphical depictions are provided to analyze the velocity, temperature and nanoparticle concentration fields under the influence of various pertinent parameters. Furthermore, local skin friction, local Nusselt and Sherwood numbers are quantitatively presented and discussed. A comparison with previous results demonstrates good agreement.

This study uniquely integrates multiple factors influencing boundary layer flow in electrically conducting nanofluids, offering a nuanced understanding of heat and mass transfer over radially stretching surfaces. By using advanced numerical methods, it provides valuable insights and quantitative data that can inform practical applications in engineering and materials science.

The purpose of this study is to examine how fluid flow and heat transfer are affected by the influence of hybrid nanofluids flowing across a stagnation zone of a stretching curved surface. Stagnation point flow has garnered considerable attention over the past few decades. This is because many technical applications, such as the cooling of nuclear reactors and rotating equipment divisions, rely on stagnation-point flow.

A thorough analysis is conducted of the impacts of several regulating parameters on fluid flow and thermal performance, including the radiation parameter, heat source parameter, mixed convection parameter, porosity parameter curvature and nanoparticle concentration. The laws governing the field of flow equations are transformed by similarity substitutions into two nonlinear ordinary differential equations, which are then solved numerically using Maple. The MR-Solve technique in the built-in Maple package was used. The MR-Solve technique was used to numerically solve highly coupled ordinary differential equation problems. This approach produced highly precise and consistent results. It also provides the best performance while using a minimum amount of CPU and the shortest phrases.

The main conclusions of this study show that axial velocity drops, while radial velocity increases as the mixed convection parameter increases. The rate of heat transmission and skin friction is higher for hybrid nanoparticles with volume fraction percentile (0.01–0.03) than for those with volume fraction percentile (0.1–0.3).

Further research on this topic could examine a broader range of parameter values, suction/injection, entropy, mass equation, micropolar fluid, ternary hybrid nanofluid and Newtonian heating flow on a curved stretching surface.

By investigating a novel physical design that combines the various effect with stagnation flow, this study adds value and offers insights and prospective improvements in the discipline of heat fluid mechanics. Mathematical modeling or experimental studies in a variety of multiphysical contexts can be used to achieve this. Heat exchangers, crystalline procedures, microelectronic machines, systems for conserving energy, integrating operations, food manufacturing, climate control, purification and other engineering domains can all benefit from the geometric configurations investigated in this study. The results of this study greatly aid in optimizing thermal performance in a variety of application domains. This study is novel because it compares several volume fraction percentiles.

A stretching curved surface’s stagnation zone is traversed by hybrid nanofluids, offering insights into how curvature affects heat transfer and fluid flow efficiency. The results aid in the design and improvement of the energy transfer efficiencies for a range of commercial and biological purposes. The results offer possibilities for increased efficiency in a range of applications by developing hybrid nanofluid flow control methods and helping to create ideal thermal systems.

Nanofluids are used in technology, engineering processes and thermal exchanges. In thermal transfer processing, these are used for the smooth transportation of heat and mass through various mechanisms. In the current investigation, we have examined multiple effects like activation energy thermal radiation, magnetic field, external heat source and especially slippery effects on a bioconvective Casson nanofluid flow through a stretching cylinder.

Several studies used non-Newtonian fluid models to study blood flow in the cardiovascular system. In our research, Lewis numbers for bioconvection and the influence of important parameters, such as Brownian diffusion and thermophoresis effects, are also considered. This system is developed as a partial differential equation for the mathematical treatment. Well-defined similarity transformations convert partial differential equation systems into ordinary differential equations. The resultant system is then numerically solved using the bvp4c built-in function of MATLAB.

After utilizing the numerical approach to the system of ordinary differential equations (ODEs), the results are generated in the form of graphs and tables. These generated results show a suitable accuracy rate compared to the previous results. The consequence of various parameters under the assumed boundary conditions on the temperature, motile microorganisms, concentration and velocity profiles are discussed in detail. The velocity profile decreases as the Magnetic and Reynolds number increases. The temperature profile exhibits increasing behavior for the Brownian motion and thermal radiation count augmentation. The concentration profile decreased on greater inputs of the Schmidt number and magnetic effect. The density of motile microorganisms decreases for the increased value of the bio-convective Lewis number.

The numerical analysis of the flow problem is addressed using graphical results and tabular data; our reported results are refined and novel based on available literature. This method is useful for addressing such fluidic flow efficiently.

High surface area-to-volume ratios make nanoparticles ideal for cancer heat therapy and targeted medication delivery. Moreover, ternary nanofluids (TNFs) may possess superior thermophysical properties compared to mono- and hybrid nanofluids due to their synergistic effects. In light of this information, the objective of this article is to examine the blood-based TNF flow within convergent/divergent channels under velocity slip and temperature jump.

Leading partial differential equations corresponding to the problem are transformed into a system of nonlinear ordinary differential equations by using similarity variables. The bvp4c code that uses the finite difference method is used to obtain a numerical solution.

The effect of nanoparticles may change depending on the characteristics of flow near the wall. The properties and proportions of the used nanoparticles become important to control the flow. When TNF was used, an increase in the Nusselt number between 4.75% and 6.10% was observed at low Reynolds numbers. At high Reynolds numbers, nanoparticles reduce the Nusselt number and skin friction coefficient values under some special flow conditions. Importantly, the effects of second-order slip on engineering parameters were also investigated. Furthermore, the Nusselt number increases with increasing shape factor.

Obtained results of the study can be beneficial in both nature and engineering, especially blood flow in veins.

The main innovations of this study are the usage of blood-based TNF and the examination of the effect of shape factor in convergent/divergent channels with second-order velocity slip.

This study aims to perform a comprehensive comparative analysis of the performance of microchannel heat sinks (MCHS) across a wide range of operating conditions. It investigates the interplay between heat transfer efficiency, frictional effects and flow dynamics in different channel configurations and fluid types.

The analysis is conducted through numerical simulations, solving the governing equations for mass, momentum and energy conservation. Multiple channel geometries are evaluated, each incorporating specific strategies to disrupt the thermal boundary layer along the heated channel surface. The study also considers the influence of transverse vorticity effects arising from abrupt or smooth geometric variations. The performance is assessed for three distinct fluids – mercury, helium and water – to examine the complex interplay between fluid properties (e.g. viscosity and thermal diffusivity), momentum losses and heat transfer gains. Key parameters, including the Reynolds number and Prandtl number, are systematically varied to uncover their impact on heat transfer coefficients, vorticity distribution and flow stability.

The study reveals that microchannels with wavy geometries and double internal bifurcations consistently deliver superior thermal performance compared to other configurations, regardless of the working fluid. The results highlight that variations in the Prandtl number significantly influence the dimensional convective heat transfer coefficient, vorticity patterns and the onset of fluid-dynamic instabilities for a fixed Reynolds number and geometry. The authors introduce a correlation for the Nusselt number with the exponents for the Reynolds and Prandtl numbers being ½ and ¼, respectively; the authors also show that, in agreement with existing literature, the friction factor is primarily affected by the Reynolds number and channel shape, demonstrating no dependence on the Prandtl number.

This research provides novel insights into the non-linear scaling of heat transfer and momentum loss with fluid properties in MCHS. The systematic exploration of fluid and geometric interactions enriches the current understanding of microchannel heat transfer mechanisms, presenting actionable recommendations for real-world applications.