Heat and mass transfer enhancement in magnetohydrodynamics nanofluids through porous media with radiation, joule heating, and viscous dissipation considerations

The miniaturization of modern device induces appreciably hike in the operating temperature, motivating the research on micro-scale heat transfer to improve the thermal management in confined space. Convective heat transfer in microchannel becomes a topical subject in view of its efficiency in the thermal regulation of micro-scale devices. However, the inherently poor thermal conductivity of conventional fluid poses a primary limitation on the thermal performance and compactness of the cooling devices. Nanofluid, a novel type of engineered colloid consisting of suspended nanoparticles, exhibits a promising potential to be the high-performance heat transfer medium due to its notable enhanced thermal conductivity. The early research focused on the thermophysical properties of nanofluid whereby the study on micro-scale convective transport of nanofluid is comparatively scarce. Therefore, the understanding on the micro-scale convection of nanofluid is still in the infancy stage, urging the need of extensive research on the subject to explore the potential of nanofluid in micro-scale thermal system. This thesis presents a comprehensive analysis on the convective transport of nanoparticle-suspension in micro-scale cooling devices, aiming to investigate various pertinent effects of nanofluid convection from the point of view of the first law and the second law of thermodynamics. Starting from the basic physical laws, analytical models are developed to investigate the effects of streamwise conduction and viscous dissipation on forced convection of nanofluids in microchannels. Subsequently, the analysis is extended to thermal non-equilibrium porous microchannels to scrutinize the performance of nanofluid flow under the effects of internal heat generations and thermal asymmetries. Analysis of the first law of thermodynamics reveals that the streamwise conduction, which is significant in low-Peclet-number flow, is greatly amplified in nanofluid. On the other hand, the viscous dissipation effect intensifies with the increase of nanoparticle volume fraction and Reynolds number, leading to heat transfer performance deterioration. Nanofluid outperforms its base fluid only when the nanoparticle diameter and the Reynolds number are lower than the threshold values. Besides, the heat transfer enhancement of nanofluid is the largest when the microchannel is heated symmetrically, and occurs over a larger range of Reynolds number when the porous-medium solid-phase heat generation is significant. Analysis of the second law of thermodynamics shows that the streamwise conduction in nanofluid induces a distinctive entropy generation characteristic in low-Peclet-number flow. With an increase of Reynolds number, the streamwise conduction effect diminishes while the viscous dissipation effect increases, intensifying the bulk temperature of nanofluid along the microchannel. Consequently, streamwise entropy generation of viscous dissipative nanofluid convection becomes indispensable. Similar to the first-law analysis, nanofluid enhances the exergetic effectiveness of microchannel when the nanoparticle diameter and the Reynolds number are lower than the threshold values. For nanofluid flow in porous media, the enhancement occurs only when the internal heat generations are relatively low. The entropy generation of nanofluid can be minimized with respect to the Reynolds number and the wall heat flux ratio, providing the ideal operating condition which optimizes the second-law performance of nanofluid flow in micro-scale device.

We investigate the steady boundary layer mixed convective flow over a horizontal impermeable wall embedded in a porous medium filled with a water-based nanofluid. The model used for the nanofluid incorporates the effects of the volume fraction parameter. The main objective of the present study is to investigate viscous dissipation and Soret effects on heat and mass transfer in a nanofluid containing Al2O3 and TiO2 nanoparticles. The temperature and concentrations at the wall were kept constant. A similarity transformation was used to obtain a system of nonlinear ordinary differential equations. The resulting nonlinear governing equations with associated boundary conditions were solved numerically using the Matlab bvp4c solver. The effects of viscous dissipation and the Soret parameter on dimensionless temperature, concentration, heat and mass transfer are presented graphically. It was observed that the heat transfer rate decreased with an increase in nanoparticle volume fraction. Comparison of current and previously published results (Lai and Kulaki [10], Arfin et al. [12]) showed a good agreement.

Purpose Industrial fluids with shear-dependent viscosity, such as polymer melts, biological fluids and nanoparticle suspensions, play a vital role in engineering applications, including electromagnetic flow control, electronic cooling, metallurgical processes, magnetohydrodynamics (MHD) pumps and energy systems. To achieve realistic modeling, this study aims to investigate simultaneous heat and mass transfer in a non-Newtonian cross fluid containing mono-, di- and tri-nanoparticles over a heated stretching surface. Key engineering indicators – skin friction coefficient, Nusselt number and Sherwood number – are analyzed to support the design of efficient thermal systems. The effects of Joule heating, viscous dissipation, free-stream velocity and homogeneous chemical reaction on flow, thermal and concentration fields are also examined. Design/methodology/approach The governing equations are formulated using boundary layer approximations and transformed into similarity-based boundary value problems. These are solved numerically using the finite element method (FEM) because of its robustness, accuracy and suitability for nonconservative systems. The original two-dimensional problem is reduced to a one-dimensional form, ensuring computational efficiency. Findings The results demonstrate that tri-nanofluids provide superior heat transfer performance, yielding the maximum wall heat flux. In contrast, di-nanofluids exhibit the highest wall shear stress compared to mono- and tri-nanofluids. Joule heating significantly increases fluid temperature and deteriorates thermal efficiency, highlighting the importance of minimizing Ohmic dissipation in magnetically influenced thermal systems. Originality/value This study presents a novel FEM-based comparative framework to distinguish the thermal and hydrodynamic behaviors of mono-, di- and tri-nanoparticle-enhanced Cross fluids under MHD conditions. The findings offer quantitative insights into heat and mass transfer enhancement and provide practical guidance for optimizing advanced cooling and electromagnetic fluid systems.

Purpose The current analysis investigates the classification of thermal transport of tri-hybrid radiative viscous nanofluid with the Hall current aspect over a rotating disk. The chief motive of the research is to link Hall currents, radiation and rotating geometries in optimizing the thermal performance of nanofluids. Design/methodology/approach The integration of intelligent machine learning techniques, such as the Levenberg–Marquardt Neural Network (LM-NN), in modeling nanofluid behavior is motivated by the need for precise and efficient solutions to complex flow phenomena. Methodology The governing partial differential equations (PDEs) representing the ternary radiative viscous nanofluid flow with effects of uniformly shaped nanoparticles, Hall current, and radiative heat transfer are formulated. A hybrid computational framework, LM-NN, is used for numerical prediction of temperature and velocity fields after converting PDEs into ordinary differential equations (ODEs). Findings Velocity profile of tri-hybrid nanofluid (THNF) decreases with augmented values of magnetic parameters because of the strong impact of Lorentz force. Increasing values of the Hall current parameter cause a decline in the velocity profile. The best validation performance for the Hall current parameter is noted at 2.34e−06 for 1,000 epochs. Increasing values of the unsteadiness parameter (S) intensified the temperature profile, and the best validation performance was noted at 2.0782e−06 for 1,000 epochs. Originality/value Enhanced heat transport mechanism in Trihybrid Carreau nanofluid flows by using a rotating disk. Integration of diverse factors such as viscous dissipation, uniform heat sink/source and thermal radiation in the physical model. Incorporation of magnetohydrodynamics (MHD) and Hall current consequences in a flow of THNF. Dual computational approaches such as bvp4c and LM-NN. Role of emerging parameters on velocity and temperature profile via MATLAB illustrations and statistical data.

Entropy analysis in electrical magnetohydrodynamic (MHD) flow of nanofluid with effects of thermal radiation, viscous dissipation, and chemical reaction

Magnetohydrodynamics (MHD) has various applications in the field of medicine, particularly in drug delivery and hyperthermia treatment for cancer therapy to the affected area via peristaltic phenomena. Further elaboration is required to optimize the delivery method of hybrid nanoparticles with aluminum oxide and zinc oxide to the target area via the esophagus to get the best-desired results. Keeping the importance of MHD in mind, the present problem highlights the characteristics of Magnetohydrodynamics (MHD) peristaltic transport by incorporating the properties of nanoparticles of aluminum and zinc oxides when suspended in water through an asymmetric curved conduit. The governing equations are mathematically modeled under consideration of Hall current, viscous dissipation, ohmic heating, thermal radiation, and heat sink/source effects. The influence of magnetic field, velocity, and thermal slips is also considered. Negligible Reynolds number and long-wavelength approximations are used to overcome the complexity of the system. To compute the numerical solutions of the simplified nonlinear system, two different techniques are utilized via MATLAB and Mathematica. The outcomes of the different flow parameters on the hybrid nanofluid’s velocity, trapping phenomena, temperature distribution, heat transfer rates, and pressure gradient are analyzed through tables and graphs.

In this article a couple stress magneto-hydrodynamic (MHD) nanofluid thin film flow over an exponential stretching sheet with joule heating and viscous dissipation is considered. Similarity transformations were used to obtain a non-linear coupled system of ordinary differential equations (ODEs) from a system of constitutive partial differential equations (PDEs). The system of ordinary differential equations of couple stress magneto-hydrodynamic (MHD) nanofluid flow was solved using the well-known Homotopy Analysis Method (HAM). Nusselt and Sherwood numbers were demonstrated in dimensionless forms. At zero Prandtl number the velocity profile was analytically described. Furthermore, the impact of different parameters over different state variables are presented with the help of graphs. Dimensionless numbers like magnetic parameter M, Brownian motion parameter Nb, Prandtl number Pr, thermophoretic parameter Nt, Schmidt number Sc, and rotation parameter S were analyzed over the velocity, temperature, and concentration profiles. It was observed that the magnetic parameter M increases the axial, radial, drainage, and induced profiles. It was also apparent that Nu reduces with greater values of Pr. On increasing values of the Brownian motion parameter the concentration profile declines, while the thermophoresis parameter increases.

This research addresses the complex dynamics of hybrid Casson nanoliquids in flow and heat transfer applications, focusing on the interaction between fluid dynamics and thermal phenomena in the presence of magnetohydrodynamics (MHD), viscous dissipation, and Joule heating. The motivation behind this study stems from the need to enhance the efficiency of heat transfer processes in various engineering applications, such as cooling systems and electronic devices, where hybrid nanofluids can offer superior thermal performance compared to conventional fluids. The novelty of this work lies in its comprehensive numerical investigation of a hybrid Casson nanoliquid over a moving permeable surface, incorporating a detailed analysis of MHD effects, viscous dissipation, and Joule heating. Using the Tiwari and Das model to formulate the governing equations, the study employs similarity transformations to convert these equations into a system of ordinary differential equations (ODEs). MATLAB is then used to derive numerical solutions, with a stability analysis ensuring the physical dependability of these solutions. Key findings reveal that the temperature distribution of the hybrid nanoliquid shows a positive correlation with both Prandtl and Hartmann numbers. Additionally, a positive relationship between temperature and the Eckert number is observed. These insights offer valuable guidance for engineers aiming to optimize heat transfer processes using hybrid nanofluids, highlighting their potential for improved thermal management in practical applications.

Purpose This study aims to investigate magnetohydrodynamic (MHD) flow and heat transfer over a nonlinear permeable stretching/shrinking sheet, incorporating the effects of viscous dissipation and Joule heating. This work addresses the gaps in understanding dual solutions and stability in such systems, with implications for industrial and thermal management applications. Design/methodology/approach The governing partial differential equations are reduced to a system of ordinary differential equations through the application of similarity transformations. Analytical solutions for reduced skin friction and heat transfer coefficients are derived under specific parametric conditions. Physical insights are extracted through graphical and tabular representations of key parameters: suction strength, Prandtl number, magnetic field intensity, viscous dissipation, mass flux and sheet shrinking rate. Findings Dual solutions (upper and lower branches) emerge for the shrinking sheet case, with the upper branch extending as suction increases. Stability analysis confirms the lower branch’s instability. Parametric studies reveal that suction, viscous dissipation and Joule heating significantly influence temperature profiles and boundary layer thickness, whereas magnetic effects dominantly alter flow dynamics. Practical implications The findings are critical for industrial processes involving stretching/shrinking sheets, such as polymer extrusion, glass production and metal rolling. Unlike stretching flows, shrinking sheet flows exhibit backward-flow behavior, necessitating external forces (e.g. suction or imposed flow) to stabilize the boundary layer. This study provides actionable strategies for optimizing thermal regulation and flow control in such systems. Originality/value This work advances the understudied area of MHD flow with combined viscous and Joule heating effects on nonlinear permeable sheets. Novel contributions include the identification of critical thresholds for dual solutions, stability characterization and the application of asymptotic methods to resolve complex ordinary differential systems. The results offer a framework for enhancing efficiency in thermal-fluid systems reliant on conductive media.

The present study investigates the flow and heat transfer characteristics of blood carrying gold nanoparticles in a porous channel with moving/stationary walls in the presence of thermal radiation. Blood is considered as Newtonian fluid which is the base fluid and gold (Au) as nanoparticles. The governing equations are transformed into system of ordinary differential equations by using similarity transformations. The analytical solutions are obtained for the flow variables by employing homotopy analysis method (HAM). The analytical solutions are compared with the numerical solutions which are obtained by shooting technique along with Runge-Kutta scheme. It was noticed that there is a good agreement between analytical and numerical results. The influence of various parameters on velocity, temperature and heat transfer rate of gold-blood nanofluid has been discussed in detail. The temperature of the nanofluid increases with increasing the nanoparticle volume fraction. The heat transfer rate at the top wall increases with increasing nanoparticle volume fraction while it decreases for a given increase in radiation parameter.

In this study, the laminar forced convection heat transfer of copper–water nanofluid in a 2D microchannel with one wall insulated and the other with constant heat flux is simulated numerically. In this paper, two-phase lattice Boltzmann method is used for simulation of the problem considering the intermolecular forces such as drag, buoyancy, Brownian, van der Waals and Born forces. The collision and streaming equations are used for both phases separately, and the effect of nanoparticles volume fraction on the velocity and temperature profiles is examined. It is observed that velocity decreases with increasing the nanoparticles volume fraction. Moreover, an increase in nanoparticles volume fraction raises the mean fluid temperature and increases the heat transfer rate. Further, the effect of an increase in nanoparticles volume fraction and their diameter changes on the Nusselt number variations in the microchannel is investigated. Also, the effect of considering viscous dissipation on the Nusselt number in different nanoparticle volume fractions is compared to the state without considering it. Finally, the effect of Reynolds number on Nusselt number is investigated.

The entropy generation of magneto-hydrodynamic mixed convection flow of nanofluid over a nonlinear stretching inclined transparent plate embedded in a porous medium due to solar radiation is investigated numerically. The nanofluid is made of Cu nanoparticles with water as the base fluid. The two-dimensional governing equations, in presence of the effects of viscous dissipation, variable magnetic field and solar radiation are transformed by similarity method to two coupled nonlinear ODEs and then solved using the numerical implicit Keller-Box method. The effects of various parameters such as nanoparticle volume fraction, magnetic parameter, porosity, effective extinction coefficient of porous medium, diameter of porous medium solid particles and Eckert, Brinkman and Hartman numbers is investigated on velocity, temperature and entropy generation number profiles. The results reveal that near to the plate surface the increase of nanoparticle volume fraction, porosity and porous medium geometric parameter cause the entropy generation number to increase, but far enough from the plate surface the increase of nanoparticle volume fraction, porosity and porous medium geometric parameter cause the entropy generation number to decrease. Also the entropy generation number increases with the increase of Brinkman number and Hartman number, and this increase is dominant near the plate surface. Closer to the plate surface the reduction of Eckert number causes the increase of entropy generation number, but the entropy generation number increases with the increase of Reynolds number.

The magnetohydrodynamic (MHD), forced convective, rotating flow of nanofluid is investigated induced by eccentric rotations of a unsteady stretching porous disk and that of the fluid at infinity. The fluid is assumed to be incompressible, viscous, and electrically conductible. The disk and fluid away from the disk rotate about non-coincident axes at the same angular velocity. The forced convection is due to the temperature gradient between the uniform temperatures of the disk and that of the fluid far away from the disk. Consideration of the Joule heating as well as viscous dissipation have been taken into account. Nanofluids based on copper, alumina, and titania have also been assumed. Exact solution has been carried out for the velocity field. Numerical solution, on the other hand, is obtained using Crank–Nicolson algorithm for the temperature profiles. Several physical aspects of the investigation are discussed and explained by means of dimensionless parameters, Prandtl number Pr, Eckert number Ec, porosity parameter S, magnetic parameter [Formula: see text] and unsteady stretching parameter. With increasing nanoparticle volume fraction, the velocity profile is reduced, while the thickness of the boundary layer upsurges. As the unsteady parameter C gets higher values, the velocity profile enhanced whereas the temperature profile gets weaker. Fluid temperature decreases as suction parameter S raises.

The fourth order Runge-Kutta integration scheme coupled with numerical shooting algorithm is employed to examine heat and mass transfer in a steady two-dimensional Magnetohydrodynamic non-Newtonian fluid flow over a stretching vertical surface with suction by considering radiation, viscous dissipation, Soret and Dufour effects. A steady two-dimensional magneto hydrodynamic non-Newtonian fluid flow over a flat surface with suction has been studied. The boundary layer governing partial differential equations are derived by considering the Bossiness approximations. These equations are transformed to nonlinear ordinary differential equations by the techniques of similarity variables and are solved analytically in the presence of buoyancy forces. The effects of different parameters such as magnetic field parameter, Prandtl number, buoyancy parameter, Soret number, Dufour number, radiation parameter, Brinkmann number, suction parameter and Lewis number on velocity, temperature, and concentration profiles are presented graphically and in tables and discussed quantitatively. Results show that the effect of increasing Soret number or decreasing Dufour number tends to decrease the velocity and temperature profiles (increase in Soret cools the fluid and reduces the temperature) while enhancing the concentration. Among the many importance of the fluid in chemical engineering, metallurgy, polymer extrusion process will definitely require cooling the molten liquid to further cool the system, for the production of paper and glass. In this process, the rate of cooling and shrinking influences very much on the final quality of the product.

This paper investigates MHD steady flow of viscous nanofluid due to a rotating disk. Water is treated as a base fluid and copper as nanoparticle. Nanofluid fills the porous medium. Effects of partial slip, viscous dissipation and thermal radiation are also considered. Similarity transformations reduce the nonlinear partial differential equations to ordinary differential equations. Flow and heat transfer characteristics are computed by HAM solutions. Also computations for skin friction coefficient and Nusselt number are presented and examined for pertinent parameters. It is noted that higher velocity slip parameter decreases the radial and azimuthal velocities while temperature decreases for larger values of the thermal slip parameter. Also the rate of heat transfer enhances when the nanoparticle volume fraction increases.