Heat transfer enhancement in Darcy–Forchheimer Jeffrey–Hamel flow of a partially ionized power-law nanofluid under Hall and ion-slip effects

Cattaneo-Christov heat and mass fluxes model of Casson fluid employing non-Fourier double diffusion theories with ion slip and Hall effects

In the present work, steady-state hydromagnetic analysis and flow formation of Newtonian viscous fluid through a vertical microporous channel is studied theoretically. The transport governing equations include the effect of Hall current and ion-slip effects in the microchannel slip regime. Unlike the usual employed thermal properties of constant heat flux/temperature at the boundary, the current work assumes that the microporous walls are influenced by different surrounding wall temperatures. Solution to the governing equations depending on Prandtl number, rarefaction parameter, Hall current parameter, ion-slip parameter, Hartmann number and suction/injection parameter are obtained by utilizing the method of undetermined coefficient. Results demonstrating the effect of these parameters on different flow features are presented graphically in MATLAB. The results reveal that in the simultaneous occurrence of Hall and ion-slip currents, higher values of rarefaction parameter enhance the momentum boundary layer in both primary and secondary flow directions. In addition, results from this analysis also reveal that the main component of fluid velocity remains unaffected to higher values of Hall current, whereas it decreases along the induced flow directions. Furthermore, for a specific value of Hall parameter and ion-slip current, injection weakens the buoyancy drive resulting in a reduction in volume flow rate. The contrast is true with suction.

The presence of a partially ionized gas around a hypersonic vehicle permits the application of magnetohydrodynamic (MHD) devices during re-entry. The operation of such MHD devices on a re-entry vehicle will largely depend on the magnitude of the electrical conductivity of the gas between the electrodes. In some cases it may be necessary to seed the air in order to insure high conductivity. The operation of the re-entry vehicle at relatively low gas densities and high magnetic fields will produce Hall and ion slip effects which may materially reduce the effective conductivity between the electrodes. The electrical conductivity including Hall and ion slip effects for air is presented for a wide range of pressures and temperatures and for a typical re-entry vehicle, with and without seeding. The electrical conductivity is evaluated for equilibrium conditions considering the number density and collision cross sections for electrons, neutrals, and ions. The Hall and ion slip effects are evaluated from the degree of ionization, the cyclotron frequency, and the time between collisions for electrons, neutrals, and ions.

PurposeThis paper addresses the three-dimensional flow of viscous nanofluid bounded by two plates. The lower plate stretches while the upper plate remains stationary. The fluid is electrically conducting in the presence of an applied magnetic field. In addition, the Hall, ion slip and Joule heating effects are retained. Governing equations for the considered physical happening are modeled under the phenomenon of boundary layer analysis.Design/methodology/approachBoth analytical and numerical solutions for the resulting nonlinear system are derived. Numerical solutions have been presented by using bvp4c and NDSolve techniques. The homotopy analysis method is utilized for the development of convergent analytical solutions. A comparative study for the presented solutions is made. An excellent agreement between analytical and numerical solutions is noticed.FindingsThe dimensionless velocities, temperature and concentration are examined physically by two-dimensional plots, stream plot and tabular values. It is observed that Hall and ion slip parameters reduce the velocity field and temperature profile increases for the mounting values of the Eckert number.Originality/valueThis manuscript contains the novel contents which comprise the Hall and ion slip effects for the transportation of heat and mass for the flow of viscous nanofluid.

For enhancement of heat and mass transfer, the use of hybrid nano-particles in shear rate-dependent viscous fluid is of great significance given applications. In this study, we have considered the impacts of Hall and ion-slip currents on the three-dimensional (3D) flow of shear rate-dependent viscous fluid. The shear rate-dependent rheology is characterized by the Carreau-Yasuda model. Ethylene glycol is found in plasma and rheological characteristics are best described by the power-law constitutive model which is a special case of the Carreau-Yasuda rheological model, Therefore, the most generalized model is considered to examine the rheological characteristics. Further, Al 2 O 3 − ethylene glycol and TiC − Al 2 O 3 − ethylene glycol are termed as Carreau-Yasuda nanofluid and Carreau-Yasuda hybrid nanofluids respectively. Specifically, here in the considered problem, Titanium carbide and aluminum oxide (TiC and Al 2 O 3) hybrid nano-particles which are source materials for MXenes, are dispersed in the Ethylene glycol (C 2 H 6 O 2) as a base fluid. The finite element method (FEM) is implemented to find the numerical solution of the boundary value problems. The thermal performance of both types of fluids is analyzed under the influence of related parameters. The thermal performance of both types of fluids is compared. Hall and ion-slip currents are induced to the ion and electron collisions and cause Hall and ion-slip forces which have the opposite direction to the magnetic force induced due to the magnetic field interaction. Thus Hall and ion-slip forces are favorable forces and result in to increase in momentum boundary layer thickness (MBLT). It is also discovered that the Hall and ion-slip forces in TiC − Al 2 O 3 − ethylene glycol flow are greater than those in Al 2 O 3 − ethylene glycol flow. Furthermore, Hall and ion-slip currents play an important role in decreasing Ohmic dissipation, which has a negative impact on the thermal performance of the working fluid. The role of generative chemical reaction on the transport of mass is opposite to the role of the destructive chemical reaction. Joule heating (Ohmic dissipation) directly affects the temperature of fluid particles and their kinetic energy increases and hence thermal boundary layer thickness (TBLT) becomes wider. Thus Ohmic dissipation has adverse effects on thermal performance. Thus fluids with no dissipation behave better as coolants.

Heat transfer enhancement in partially ionized Williamson fluid using tri-nanoparticles has not been studied yet. This article provides a comparative analysis of the enhancement of heat and mass transfer in Williamson fluids for mono, hybrid, and tri-nanoparticles. This is a theoretical study based on mathematical modelling using governing laws of heat transfer in a fluid medium (here fluid medium is Williamson fluid). The system of governing PDEs is transformed via a change of variables suggested under the similarity principle. Finite element method (FEM) is implemented to solve the dimensionless problems. Computer code is tested and convergent meshed free solutions are computed. Aluminium oxide, titanium oxide, and silicon oxide are taken as tri-nanoparticles whereas ethylene glycol is considered plasma and is subjected to the applied magnetic field of non-uniform intensity. An optimized improvement in thermal performance is noticed for the cause of tri-nanoparticles. The wall of heat transfer rate for mono, hybrid, and tri-nanofluids was computed and their numerical values are compared. It is noted that the wall heat transfer rate by tri-nanofluid is maximum in respect of wall heat transfer rates by mono and hybrid nanofluids. Wall shear stress exerted by tri-nanofluid is noted to have a minimum value in comparison with the wall shear stress exerted by mono and hybrid nanofluids. Hall and ion slip effects on the flow of tri-nanofluid are stronger than those on the flow of mono and hybrid nanofluids.

Hall, ion slip and ohmic heating effects in thermally active sinusoidal channel

The aim of present delivery is to address the peristaltic mechanism of a non-linear viscoelastic fluid in a compliant wall channel. Ion and Hall slip effects are considered. Heat transfer is analyzed by taking the effects of Ohmic and viscous dissipations. The problem is analyzed and formulated using regular perturbation method. Solutions of velocity, temperature, stream function and heat transfer coefficient are derived. Effects of various flow parameters on the flow quantities are examined through graphs.

The purpose of this research is to inspect the mixed convection flow of Eyring-Powell nanofluid over a linearly stretching sheet through a porous medium with Cattaneo–Christov heat and mass flux model in the presence of Hall and ion slip, permeability, and Joule heating effects. Proper similarity transforms yield coupled nonlinear differential systems, which are solved using the spectral relaxation method (SRM). The story audits show that the present research problem has not been studied until this point. Efficiency of numerous parameters on velocity, temperature, and concentration curves is exposed graphically. Likewise, the numerical values of skin friction coefficients, local Nusselt, and Sherwood numbers are computed and tabulated for some physical parameters. It is manifested that fluid velocities, skin friction coefficients, local Nusselt, and Sherwood numbers promote with the larger values of Eyring-Powell fluid parameter ε. It is also noticed that primary velocity promotes with larger values of mixed convection parameter λ, Hall parameter βe, and ion slip parameter βi, while the opposite condition is observed for secondary velocity, temperature, and concentration. Furthermore, comparative surveys between the previously distributed writing and the current information are made for explicit cases, which are examined to be in a marvelous understanding.

In this paper, we prove a regularity criteria and the local well-posedness of strong solutions to the magnetohydrodynamics with the Hall and ion-slip effects in a smooth bounded domain. Moreover, for the magnetohydrodynamics with the Hall effect and without ion-slip effect, we prove the global stability of strong large solutions. These results are obtained under an integrable property that depends on a new vorticity boundary condition which is motivated by the generalized Navier-slip boundary condition involving the vorticity.

This article describes the incompressible two-dimensional heat and mass transfer of an electrically conducting second-grade fluid flow in a porous medium with Hall and ion slip effects, diffusion thermal effects, and radiation absorption effects. It is assumed that the fluid is a gray, absorbing–emitting but non-scattering medium and the Rosseland approximation is used to describe the radiative heat flux in the energy equation. It is assumed that the liquid is opaque and absorbs and emits radiation in a manner that does not result in scattering. It is considered an unsteady laminar MHD convective rotating flow of heat-producing or absorbing second-grade fluid across a semi-infinite vertical moving permeable surface. The profiles of velocity components, temperature distribution, and concentration are studied to apply the regular perturbation technique. These profiles are shown as graphs for various fluid and geometric parameters such as Hall and ion slip parameters, radiation absorption, diffusion thermo, Prandtl number, Schmidt number, and chemical reaction rate. On the other hand, the skin friction coefficient and the Nusselt number are determined by numerical evaluation and provided in tables. These tables are then analysed and debated for various values of the flow parameters that regulate it. It may be deduced that an increase in the parameters of radiation absorption, Hall, and ion slip over the fluid region increases the velocity produced. The resulting momentum continually grows to a very high level, with contributions from the thermal and solutal buoyancy forces. The temperature distribution may be more concentrated by raising both the heat source parameter and the quantity of radiation. When one of the parameters for the chemical reaction is increased, the whole fluid area will experience a fall in concentration. Skin friction may be decreased by manipulating the rotation parameter, but the Hall effect and ion slip effect can worsen it. When the parameter for the chemical reaction increases, there is a concomitant rise in the mass transfer rate.

A comprehensive understanding of the interaction between electromagnetic fields and weakly ionized plasma layer is crucial for modeling magnetohydrodynamic (MHD) manipulation of re-entry vehicles. In this study, a systematic framework is developed to assess the multi-process effects in weakly ionized hypersonic plasma flows under electromagnetic fields during atmospheric reentry. A decoupled modeling approach is adopted, in which the stagnation region is approximated as a one-dimensional inviscid normal shock to efficiently compute thermochemical states across a wide flight envelope (3–16 km s −1 , 0–85 km). Thermochemical non-equilibrium is modeled using Park’s two-temperature model, with both 7- and 11-species air chemistry models considered. A comprehensive parametric study is then conducted to evaluate the validity of multi-process coupling models and key plasma criteria including oscillation, cyclotron and collision of particles as well as convection and diffusion of MHD behavior. Critical electromagnetic similarity parameters—magnetic Reynolds number, Hall parameter, and ion slip parameter—are subsequently computed to determine the applicability maps where induced magnetic field, Hall effect, and ion slip effect become significant. Taking RAM C-II vehicle as an example, the results show that Hall and ion slip effects are non-negligible above 40 km and 70 km, respectively, when a 0.5 T magnetic field is applied. The induced magnetic field must be considered at velocities beyond 8 km s −1 due to the magnetic Reynolds number exceeding unity. Besides, the 11-species model is necessary above 8 km s −1 to ensure accuracy in ion species prediction. The analysis may provide physics-based criteria for selecting appropriate plasma models in hypersonic MHD flow control applications.

We study the nonlinear stability, with respect to axisymmetric perturbations, of the solution magnetic field to the induction equation for a weakly ionized gas, subjected to an assigned planar velocity field which, in a special case, keeps it in proximity of a gravitational center. In other cases, this velocity field can generate hyperbolic trajectories. Whatever, assuming the presence of Hall and ion-slip effects, we will try to determine how the geometric and kinematic characteristics of the gas stream affect the stability/instability of the magnetic field. Then, we obtain a necessary and sufficient stability condition and estimate the radius of attraction.

Hall and ion slip effects on peristaltic flow of Jeffrey nanofluid with Joule heating

Hall and ion slip effects on peristaltic flow and heat transfer analysis with Ohmic heating