Heat transfer in MHD stagnation point flow of a ferrofluid over a stretchable rotating disk

Heat transport in inclined flow towards a rotating disk under MHD

Flow towards a rotating disk is of highly practical significance in numerous engineering applications such as Turbine disks, rotary type machine systems and many more. In light of this, the current work is an attempt to explore MHD oblique flow towards a rotating disk. Hydromagnetic effects in addition to heat transfer is taken into consideration. The flow governing Partial Differential Equations are altered to a system to coupled non-linear Ordinary Differential Equations through scaling group of transformations which afterwards are tackled using Shooting Algorithm. The impact of obliqueness parameter γ, rotation ratio parameter [Formula: see text] and magnetic field parameter M on 2-dimensional and 3-dimensional stream contours are presented. Location of the shear center varies with magnetic field parameter. Heat flow at the disk surface boosts with magnet field parameter M and rotation ratio parameter [Formula: see text].

A Hydrodynamic–Elastic Numerical Case Study of a Solar Collector with a Double Enclosure Filled with Air and Fe3O4/Water Nanofluid

This work deals with a numerical investigation of a hydrodynamic–elastic problem within the framework of a double enclosure solar collector technological configuration. The solar collector presents two enclosures separated by an elastic absorber wall. The upper enclosure is filled with air, whereas the lower one is filled with Fe3O4/water nanofluid. The mathematical model governing the thermal and flow behaviors of the considered nanofluid is elaborated. The effects of imposed hot temperatures, the Rayleigh number and air pressure on the nanofluid’s temperature contours, velocity magnitude distribution, temperature evolution, velocity magnitude evolution and Nusselt number evolutions are numerically investigated. The numerical results show and assess how the increase in the Rayleigh number affects convective heat transfer at the expense of the conductive one, as well as how much the Nusselt number and the nanofluid velocity magnitude and temperature are affected in a function of the imposed hot temperature type (uniformly or right-triangular distributed on the elastic absorber wall). Moreover, the results evaluate how increases in the air pressure applied on the elastic absorber wall affects the nanofluid’s temperature distribution.

Aqua Cobalt Ferrite/Mn–Zn Ferrite Hybrid Nanofluid Flow Over a Nonlinearly Stretching Permeable Sheet in a Porous Medium

In the present article, the problem of ferro hybrid nanofluid flow over a nonlinearly stretching permeable sheet in a porous medium has been studied. The main motivation of this research is to present a comprehensive analysis of the hydrodynamics and thermal boundary layers as well as the skin friction and heat transfer as two important quantities of engineering interest for the relevant ferro hybrid nanofluid flow. The ferro hybrid nanofluid is a nanofluid that can be composed of several nanoparticles and has a magnetic property; it means that has its own behavior in the magnetic field. Two different types of ferroparticles, namely, Mn–Zn ferrite (Mn–ZnFe2O4) and cobalt ferrite (CoFe2O4) are considered with water as a base fluid. The similarity solution is used to decrease the governing set of partial differential equations (PDEs) to the nonlinear ordinary differential equations (ODEs) system, which is solved numerically by the bvp4c function of MATLAB. The effects of pertinent parameters, namely, magnetic parameter, nonlinear velocity parameter, permeability parameter, and volume fraction of the second nanoparticle on velocity and temperature profiles, skin friction coefficient, and local Nusselt number are computed and shown through graphs. The prominent novelty of this research is related to the use of ferro hybrid nanofluid as a working fluid, where many studies have been carried out in the field of the determination of heat transfer and skin friction in nanofluids/ferro nanofluids on different geometries. To the best of our knowledge, no one has ever attempted to study the present boundary layer problem with applying ferro hybrid nanofluid. The results of this paper indicate that Nusselt number and skin friction coefficient decrease with increasing magnetic field.

Numerical Analysis of Thermal Radiative Maxwell Nanofluid Flow Over-Stretching Porous Rotating Disk

The fluid flow over a rotating disk is critically important due to its application in a broad spectrum of industries and engineering and scientific fields. In this article, the traditional swirling flow of Von Karman is optimized for Maxwell fluid over a porous spinning disc with a consistent suction/injection effect. Buongiorno’s model, which incorporates the effect of both thermophoresis and Brownian motion, describes the Maxwell nanofluid nature. The dimensionless system of ordinary differential equations (ODEs) has been diminished from the system of modeled equations through a proper transformation framework. Which is numerically computed with the bvp4c method and for validity purposes, the results are compared with the RK4 technique. The effect of mathematical abstractions on velocity, energy, concentration, and magnetic power is sketched and debated. It is perceived that the mass transmission significantly rises with the thermophoresis parameter, while the velocities in angular and radial directions are reducing with enlarging of the viscosity parameter. Further, the influences of thermal radiation Rd and Brownian motion parameters are particularly more valuable to enhance fluid temperature. The fluid velocity is reduced by the action of suction effects. The suction effect grips the fluid particles towards the pores of the disk, which causes the momentum boundary layer reduction.

Magnetohydrodynamic Flow and Heat Transfer Induced by a Shrinking Sheet

The magnetohydrodynamic (MHD) stagnation point flow over a shrinking or stretching flat sheet is investigated. The governing partial differential equations (PDEs) are reduced into a set of ordinary differential equations (ODEs) by a similarity transformation and are solved numerically with the help of MATLAB software. The numerical results obtained are for different values of the magnetic parameter M, heat generation parameter Q, Prandtl number Pr and reciprocal of magnetic Prandtl number ε. The influences of these parameters on the flow and heat transfer characteristics are investigated and shown in tables and graphs. Two solutions are found for a certain rate of the shrinking strength. The stability of the solutions in the long run is determined, and shows that only one of them is stable. It is found that the skin friction coefficient f ″ ( 0 ) and the local Nusselt number − θ ′ ( 0 ) decrease as the magnetic parameter M increases. Further, the local Nusselt number increases as the heat generation increases.

Thermal Radiation and MHD Effects in the Mixed Convection Flow of Fe3O4–Water Ferrofluid towards a Nonlinearly Moving Surface

This paper investigated the magnetohydrodynamic (MHD) mixed convection flow of Fe3O4-water ferrofluid over a nonlinearly moving surface. The present work focused on how the state of suction on the surface of the moving sheet and the effects of thermal radiation influence the fluid flow and heat transfer characteristics within the stagnation region. As such, a similarity solution is engaged to transform the governing partial differential equations to the ordinary differential equations. A collocation method, namely the bvp4c function in the MATLAB software solves the reduced system, numerically. Two different numerical solutions were identified for the cases of assisting and opposing flows. The stability analysis was conducted to test the stability of the non-uniqueness solutions. The increment of the thermal radiation effect affects the rate of heat transfer to decrease. The stability analysis conveyed that the upper branch solution is stable and vice versa for the other solution.