Unsteady Magnetohydrodynamic Flow Research Articles

Unsteady magnetohydrodynamic tri-hybrid nanofluid flow past a moving wedge with viscous dissipation and Joule heating

This study aims to boost thermal convection through careful selection and adjustment of nanomaterial volumes, focusing on the unsteady magnetohydrodynamic flow past a moving wedge with viscous dissipation and Ohmic heating in a ternary nanofluid of alumina (Al2O3), copper oxide (CuO), and copper (Cu) in water. Employing mathematical modeling and numerical analysis via MATLAB's BVP4C, it explores how discharge concentration influences flow characteristics and identifies critical conditions for single or dual solutions. Key parameters such as motion and wedge parameters, Eckert number, magnetic strength, and nanoparticle volume ratios were scrutinized for their impact on fluid dynamics and heat transfer. Results show enhanced convective thermal transfer with increased nanoparticle hybridity and volume fraction, alongside suction/injection parameter (S), unsteadiness parameter (A), Eckert number (Ec), and magnetic parameter (M), albeit decreasing with wedge angle adjustments. Stability analysis revealed the stability of the initial solution vs the instability of the secondary. Introducing a novel time variable, τ=cAt(1−ct), this research demonstrates that at λ=−4.7(a leftward wedge) with a 0.04 nanoparticle volume fraction, ternary and hybrid nanofluids significantly outperform mono nanofluid, achieving thermal efficiency gains of 25.6% and 7.5%, respectively. This foundation underscores the potential of optimized nanofluid mixtures for advanced heat transfer applications.

Unsteady MHD flow analysis of hybrid nanofluid over a shrinking surface with porous media and heat generation: Computational study on entropy generation and Bejan number

The use of hybrid nanofluids in real-world situations is essential for enhancing the efficiency of heat transmission, especially in cooling semiconductor technology and industrial processes. The entropy generation on unsteady Al2O3-Cu/H2O hybrid nanofluid flow over a three-dimensional shrinking sheet is addressed numerically in this study, taking into account the effects of magnetohydrodynamic (MHD), nonlinear thermal radiation, porous media, heat generation, viscous dissipation, joule heating, and convective conditions. Using well-known non-similarity transformations, the model is carefully converted from partial differential equations (PDEs) to ordinary differential equations (ODEs). Afterwards, the behaviors of critical physical characteristics are uncovered across different parameter configurations by a numerical solution using the finite difference technique in bvp4c MATLAB. The velocity profiles of hybrid nanofluid grow proportionately with increases in the values of ϕ2,M,A,K and λ parameters. As Rd,θw,Ec,Bi,H and ϕ2 increase, the temperature of the hybrid nanofluid rises, but as M and A increase, the temperature falls. The local skin friction in both the x and y- directions is increased by enhancing the unsteadiness A, nanoparticle volume fraction ϕ2, magnetic M, porous media K, and the ratio of strain rate λ parameter on the shrinking surface. The local Nusselt number is improved by cumulative the unsteadiness A, nanoparticle volume fraction ϕ2, magnetic M, and Biot number Bi parameter in the direction of a shrinking surface, while the Nusselt number decreases when Eckert number Ec, thermal radiation Rd, heat production H, and temperature ratio θw are improved. An upsurge in the magnetic parameter leads to the development of entropy generation. Increasing levels of the magnetic parameters led to a reduction in the Bejan number. At a nanoparticle volume fraction of 1 % and a nonlinearity radiation scenario, where the unsteadiness values are 0.5, the Nusselt number for hybrid nanofluid shows an estimated improvement of 10.55 % compared to regular nanofluid.

Squeezing MHD Flow of Sodium Alginate-Based Casson Hybrid Nanofluid with Soret and Dufour Effects

Ultrahigh-performance cooling is one of the essential requirements in the industrial technology. Hence, the new heat transfer fluid, hybrid nanofluid is introduced to increase the thermal conductivity of fluid and investigated with various physical parameters. The unsteady magnetohydrodynamics (MHD) flow of Casson hybrid nanofluid through two surfaces in a permeable medium with chemical reaction are explored. The hybrid nanoparticles of Alumina and Copper is dispersed in the base fluid of sodium alginate . The discretize equations are solved using similarity transformation and Keller-box methods. The comparison of the current results with the published results for validation is conducted and discovered in proper agreement. The impacts of squeeze, magnetic, porous media, chemical reaction, heat sink/source, and Soret and Dufour on behaviour and physical quantities of flow are discussed. The graphical results show the squeeze of two surfaces accelerates the fluid velocity near the upper plate region. Further, the velocity slowing down when and increases, and it elevates as and rises in the middle of channel. The increment of heat transfer rate and temperature of fluid is shown for increasing Ec, y and Du, and the opposite behaviour is discovered with raise in. The fluid concentration decreases and the mass transfer rate enhances for rising Sr. The concentration enhance and rate of mass transfer reduce with the constructive chemical reaction, whereas contrary effects is shown for destructive chemical reaction.

Unsteady magnetohydrodynamic squeezing Darcy-Forchheimer flow of Fe3O4 Casson nanofluid: Impact of heat source/sink and thermal radiation

The paper aims to investigate the unsteady magnetohydrodynamics (MHD) flow with Darcy-Forchheimer effect and heat transportation. The system incorporates a Casson nanofluid (CNF) with heat transfer during melting and slip velocity, influenced by heat source/sink and thermal radiation. The motivation of investigating the current topic comes because of the squeeze flow is of practical physics. The mathematical process involves converting nonlinear partial differential equations (PDEs) into nonlinear ordinary differential equations (ODEs). The nonlinear ODEs are analytically solved via the Homotopy perturbation method (HPM), while considering the appropriate boundary conditions (BCs). Through a non-dimensional procedure, many dimensionless physical quantities are achieved. The primary results of velocity, temperature profiles, local skin-friction, and the local Nusselt number are shown and analyzed based on several non-dimensional parameters. It is found that the increasing of the radiation factor values, leads to a drop in the velocity and temperature of the CNF, as well as the local skin-friction and Nusselt number. Additionally, the increase of the slip velocity factor results in higher velocity, temperature, and local Nusselt number. Meanwhile, it reduces the local skin-friction.

A mathematical analysis of the unsteady magnetohydrodynamic stagnation point flow of a nanofluid consisting of single-walled carbon nanotubes and human blood through a stretchable wall with slip effects

A mathematical analysis of the unsteady magnetohydrodynamic stagnation point flow of a nanofluid consisting of single-walled carbon nanotubes and human blood through a stretchable wall with slip effects

Unsteady magnetohydrodynamic hybrid nanofluid flow over a rotating disk with viscous dissipation and Cattaneo–Christov heat flux model

This work addresses unsteady MHD flow of hybrid nanofluids (MWCNTs−Fe3O4)/H2O over a rotating disk with viscous dispassion and the Cattaneo–Christov heat flux model. The boundary layer flow-directing PDEs were converted into systems of dimensionless coupled nonlinear ODEs using the similarity conversion technique. Using the spectral quasilinearization method (SQLM), the resulting nonlinear momentum and energy equations were then numerically solved along with their boundary conditions. For the preparation of (MWCNTs−Fe3O4)/H2O hybrid nanofluid with shape factor n1=n2=3, it is specified that 5% of MWCNTs, 20% of Fe3O4, and 75% of H2O be taken. Using graphs and tables, the effects of more noticeable parameters on the thermal flow fields and velocity were thoroughly investigated. The results show that as the value of the unsteady parameter increased, the momentum and thermal boundary layer thickness decreased. The local heat transfer rate improves by nearly 20% as 0.2 volume of Fe3O4 nanoparticles dispersed in 0.1 volume of MWCNTs and 0.7 volume of H2O nanofluid. The finding of this study is noteworthy because it indicates that the (MWCNTs−Fe3O4)/H2O hybrid nanofluids exhibit superior flow distributions and good thermal property stability when compared to their mono counterparts.

Numerical simulation of unsteady magneto hydrodynamic flow of nanoparticle deposition in the porous alveolar ducts

This study aims to investigate a numerical model of dust particle deposition in the human lung. There were significant discrepancies in deposition inside each alveolate duct and between ducts of a given generation, indicating that the mean acinar concentration can be greatly exceeded by limited particle concentrations. During expiration, the huge particles try to exit the construction but are failed. The similarity transformation is used to describe the differential equations controlling the flow. The various systematic quantities, such as the fluid velocity, and dust particle velocity are determined. In this research, non-linear governing coupled partial differential equations are explained by developing a finite-difference method established on the Crank-Nicolson model that is accurate, precise, widely validated, and unconditionally stable. The technique’s precision and efficacy are proven. To show how various physical factors affect the velocity and temperature profiles, various numerical data are collected and visually displayed. For each of the characteristics tested, the results show that the nano particles’ velocity is higher in comparison to the fluid particles.

Effect of Dufour and chemical reaction on an unsteady magneto hydrodynamics flow past an exponentially moving plate

AbstractThe aim of the study is to measure the Dufour number effects on the flow patterns and heat transfer in an exponentially accelerated infinite vertical plate embedded in a porous medium in the presence of heat source and chemical reaction. Time‐dependent variations in temperature, velocity, and other factors should be taken into consideration due to the flow's unsteadiness. The fluid considered is a gray, absorbing/emitting radiation but nonscattering medium. Using the finite element method, a set of nondimensionless equations is solved analytically. Results are discussed graphically for concentration, temperature, and velocity profiles. Skin friction, Sherwood number, and Nusselt number are also explained for flow parameters through graphs.

Study of an unsteady magnetohydrodynamic‐free convective flow under parabolic ramped temperature and concentration in the presence of Soret and heat sink

AbstractThe purpose of this paper is to investigate the effects of Soret, thermal radiation, and chemical reaction on an unsteady magnetohydrodynamic free convective flow past an impulsively initiated semi‐infinite vertical plate with heat sink under parabolic ramped temperature and parabolic ramped concentration. Using some nondimensional parameters, the flow boundary equations in this case are first converted to dimensionless equations. The closed‐form Laplace transform technique is employed here to solve the partial differential equations and get the solutions for fluid velocity, temperature, and concentration. The velocity, temperature, and concentration of the fluid tend to vary with the effect of various flow factors. These changes are graphically represented and analyzed. Differences in skin friction, Nusselt number, and Sherwood number for the different relevant parameters are also recorded. The Soret number hikes the fluid velocity and concentration. The rate of heat transfer, mass transfer, and momentum transfer improves due to the application of parabolic ramped conditions.

Unsteady Magnetohydrodynamic Flow and Heat Transfer From a rotating wall

The importance of the effects of rotation and electromagnetic force on the hydrodynamic flow and their application to cosmical fluid dynamics and solar physics have drawn attention of many research workers recently. In this paper we have investigated unsteady magnetohydrodynamic flow and heat transfer from a rotating wall. The wall is taken electrically non-conducting and whole system is rotating with a constant angular velocity about an axis normal to the wall.A constant induced magnetic field has been included. The temperature distribution with distance is shown Graphically.

Bioconvection effects on the heat and mass transfer of unsteady MHD blood flow over a permeable artery

The mathematical analysis of blood’s non-Newtonian behavior in the presence of drug nanoparticles and microbes with magnetic and thermal radiation effects is the focus of the current article. The response surface methodology (RSM) is used to conduct a sensitivity study of the bioconvection impacts on the heat and mass transmission rate of the unsteady magnetohydrodynamic blood flow. The physical laws governing unsteady blood flow over stretching blood vessels are mathematically represented as a system of partial differential equations, which are numerically solved using the Fourth Order Runge–Kutta Method in conjunction with the Shooting Technique. Following an analysis of the numerical data, statistical conclusions are drawn on the heat and mass transfer rates. The impact of Brownian motion and thermophoresis factors is discovered to increase blood temperature. Additionally, at the largest Brownian motion factor and maximum thermophoresis effect, the largest heat transfer rate occurs. It is also observed that the lowest mass transfer rates are generated by higher radiation parameter and chemical reaction parameter values. The findings of the study show potential for important applications in therapeutic hypothermia, magnetic therapy, and targeted drug delivery.

Hall effect on unsteady MHD flow along vertical plate with variable temperature and mass diffusion in the presence of porous medium and chemical reaction

The effects of chemical reaction and Hall current on the unsteady magneto hydrodynamic flow along a vertical plate with variable temperature and mass diffusion in the presence of a porous medium is studied hare. The fluid flow model of this paper contains governing partial differential equations of the motion, energy, and diffusion equation. To simplify the analysis, the governing equations are transformed into dimensionless form using non-dimensional variables. The Laplace-transform technique is employed to obtain an exact solution for the flow equations of the MHD model. The results of the analysis are presented using graphical representations of the velocity profiles. With the help of graphs, we discussed the behavior of fluid velocities with different parameters, including the chemical reaction parameter, Hall currents parameter, accelerated parameter, magnetic field parameter, and permeability parameter, and the numerical values of Sherwood number have been tabulated. We found that the values obtained for velocity, concentration and temperature are in concur-rence with the actual flow of the fluid

Parameter estimation for unsteady MHD oscillatory free convective flow of generalized second grade fluid with Hall effects and thermal radiation effects

This work first establishes an unsteady magnetohydrodynamic (MHD) oscillatory free convection flow model of the generalized second grade fluid with Hall heat and mass transfer effect in a straight rectangular duct. A fast second-order spectral method with fractional backward difference formula (FBDF) is proposed to obtain the numerical solution of the established model. The distribution of the velocity and the temperature fields is discussed, and the effect of each parameter on the velocity and temperature fields is shown through graphical experiments. Moreover, in order to avoid the problems of slow computational speed and low accuracy of traditional numerical methods, new fractional physics-informed neural networks (PINNs) are proposed for the multi-parameter estimation of this model. At the same time, a comparative study of our method with the Bayesian method is presented. Experimental results show that fractional PINNs is more effective for multi-parameter estimation problems and get better accuracy at the same number of parameters.

Effectiveness of silver-magnesium oxide-water hybrid nanofluid in Couette channel

The present article numerically investigates the unsteady magnetohydrodynamic (MHD) Couette flow containing novel (Ag + MgO)-water hybrid nanofluid (HNF). The nanoparticles of silver (Ag) and magnesium oxide (MgO) are supplemented to base fluid water. The top wall is kept in uniform motion while the bottom wall of channel set stationary and stretchable. An external magnetic field is applied perpendicular to lower plate. The governed nonlinear partial differential equations (PDE) are solved employing finite difference method (FDM). The effects of hybrid nanofluid and nanofluid (NF) are compared for the significant parameters and presented graphically. The results illustrate that (Ag + MgO)-water HNF exhibits significant influence over Ag-water NF on velocity and temperature in the Couette channel.

Radiation Absorption and Diffusion Thermo Effects on Unsteady MHD Kuvshinski Fluid Flow Past an Inclined Porous Plate in the Presence of Thermal Radiation and Chemical Reaction

The aim of the present paper is to investigate investigated the Radiation absorption and diffusion thermo on unsteady magneto hydrodynamic Kuvshinski fluid flow past an infinite vertical permeable moving plate in Presence of thermal radiation, heat absorption and homogenous chemical reaction, subjected to variable suction. The plate is assumed to be embedded in a uniform porous medium and Moves with a constant velocity in the flow direction in the presence of a transverse magnetic Field. The equations governing the flow are transformed into a system of nonlinear ordinary differential equations by using perturbation technique. Graphical results for the velocity distribution, temperature distribution and concentration distribution based on the numerical solutions are presented and discussed. Also discuss the effects of various parameters on the skin-friction coefficient and the rate of heat transfer in the form of Nusselt number and rate of mass transfer in the form of Sherwood number at the surface. Velocity and temperature distribution is observed to increase with an increase in Radiation absorption and Dufour parameter, whereas diminishes with enhances of Magnetic field, heat absorption coefficient, radiation parameter and chemical reaction parameter in respective velocity, temperature and concentration distributions.

Radiation Absorption and Diffusion Thermo Effects on Unsteady MHD Casson Fluid Flow Past a Moving Inclined Plate Embedded in Porous Medium in the Presence of Chemical Reaction and Thermal Radiation

The aim of the present paper is to investigate the effects of Radiation absorption and diffusion thermo on unsteady magnetohydrodynamic Casson fluid flow past an inclined permeable moving plate in Presence of thermal radiation, heat absorption and homogenous chemical reaction. The plate is assumed to be embedded in a uniform porous medium and Moves with a constant velocity in the flow direction in the presence of a transverse magnetic Field. The equations governing the flow are transformed into a system of nonlinear ordinary differential equations by using perturbation technique. Graphical results for the velocity distribution, temperature distribution and concentration distribution based on the numerical solutions are presented and discussed. Also discuss the effects of various parameters on the skin-friction coefficient and the rate of heat transfer in the form of Nusselt number and rate of mass transfer in the form of Sherwood number at the surface. Velocity and temperature distribution is observed to increase with an increase in radiation absorption and Dufour parameter, whereas diminishes with enhances of Magnetic field, heat absorption coefficient, radiation parameter and chemical reaction parameter in respective velocity, temperature and concentration distributions.

A numerical study on MHD Cu-Al2O3/H2O hybrid nanofluid with Hall current and cross-diffusion effect

A numerical investigation has been performed to analyze an unsteady magnetohydrodynamic gravity-driven flow of a Newtonian hybrid nanofluid (Cu-Al2O3/H2O) along an impermeable vertical plate with linearly accelerated temperature and concentration. The Hall current, nanoparticle volume fraction, inclined magnetic field, and Soret effect on water-based Cu-Al2O3 hybrid nanofluid are incorporated into the flow model. The model's governing nonlinear partial differential equations are formulated and transformed into a non-dimensional form by introducing suitable variables and parameters. The finite difference method is implemented via the MATLAB solver fsolve to resolve the model equations numerically. The evolution of the primary and secondary velocities, temperature, and species concentration profiles is discussed via graphical illustration. Furthermore, a comparative analysis is performed on the coefficient of skin friction, rate of heat, and mass transport for hybrid nanofluid and nanofluid through tabular values. The novelty of the investigation reveals that a deceleration in the primary velocity and acceleration in the secondary velocity with the increasing magnetic field inclination parameter exists. The rising value of Cu nanoparticle volume fraction augments the primary, secondary skin friction coefficients, and the heat and mass transport rates at the plate. The Dufour number stimulates a reduction in the heat transport rate, while an enhancement occurs with the Soret number. The present investigation demonstrates that the heat transfer rate for water-based Cu-Al2O3 hybrid nanofluid is higher than that for water-based Cu nanofluid. The current research can be implemented to augment the efficiency of the cooling mechanism of heat exchangers, solar collectors, nuclear reactors, and many more.

Magneto-Thermo Heat Transfer of a Chemically Reactive and Viscous Dissipative Casson Nanofluid Thin Film Over an Unsteady Stretching Surface with Variable Thermal Conductivity

This paper addressed unsteady magnetohydrodynamic flow and heat transfer of an incompressible Casson nanofluid thin film past a stretching sheet by considering the features of thermal radiation, chemical reaction, and viscous dissipation. The problem is modeled mathematically, and the governing basic equations are brought into nonlinear ordinary differential equations by utilizing appropriate similarity transformations. Then the transformed equations are then solved numerically by using the bvp4c solver. The influences of pertinent physical variables are performed on velocity, temperature gradient, and nanoparticle concentration gradient profiles. It is seen that the profile of the nanoparticle concentration gradient enhances by increasing the values of the Schmidt number, whereas the opposite trends are observed by increasing the values of the thermophoresis parameter. It is also analyzed that by increasing the values of the thermophoresis parameter, there is an increase in the profiles of the temperature and concentration distributions. The computed results are obtained by giving main consideration to the convergence process and comparing them with the results existing in the literature.

English

English

Investigation of the effects of various nanoparticle morphologies on mass and heat transport in SiO2-H2O unsteady magnetohydrodynamic nanofluid flow through a stretched cylinder

This article investigates the effects of the various silicon dioxide ( Si O 2 ) nanoparticles immersed in water ( H 2 O ) base fluid on velocity and heat transport over an unsteady stretching cylinder under the influence of magnetohydrodynamics ( MHD ), velocity slip, and convective boundary conditions. The physical model is initially developed in the form of partial differential equations (PDEs) by using the conservation principle. Employing suitable transformations, the set of PDEs has been transformed into a system of Ordinary differential equations (ODEs). The nonlinear equations in the proposed model are optimally and dynamically assessed. To produce numerical solutions for nonlinear systems, MATLAB's BVP4C solver technique is used. Furthermore, the numerical technique is validated by calculating residual error. The recent investigation’s novel results include: the nanoparticles SiO 2 of play an important role in enhancing the thermal conductivity of the traditional base fluid H 2 O . The shape of the nanoparticles also plays a remarkable role in heat transfer enhancement. Increases in viscus dissipation, convective boundary conditions, and MHD parameters play a remarkable role in increasing the temperature of the nanofluid. Furthermore, platelet-shaped Si O 2 nanoparticles are reported to have the highest flow rate, highest temperature, and highest value of Nusselt numbers.