Vertical Cone In Porous Medium Research Articles

Numerical Analysis of MHD Nanofluid Flow Characteristics with Heat and Mass Transfer over a Vertical Cone Subjected to Thermal Radiations and Chemical Reaction

Nanoparticles have the ability to increase the impact of convective heat transfer in the boundary layer region. An investigation is made to analysis of magnetohdrodynamic nanofluid flow with heat and mass transfer over a vertical cone in porous media under the impact of thermal radiations and chemical reaction. In addition, thermal radiations, Hall current, and viscous and Joule dissipations and chemical reaction effects are considered. Considered three different nanoparticles types namely copper, silver, and titanium dioxide with water as base fluid. The governing equations are transformed by similarity transformations into a set of non-linear ordinary differential equations involving variable coefficients. Two numerically approaches are used to solve the transformed boundary layer system Finite Difference Method (FDM) and Chebyshev-Galerkin Method (CGM). As stated in the present analysis, it is appropriate to address a number of physical mechanisms, including velocity, temperature and concentration, as well as closed-form skin friction/mass transfer/heat transfer coefficients. Different comparisons are done with previously published data in order to validate the current study under specific special circumstances, and it is determined that there is a very high degree of agreement. The main results indicated that as the Prandtl number increases, the temperature profile decreases, but it grows for higher values of the thermophoresis parameter, Brownian motion, and Eckert number. Moreover, higher Brownian motion values lead to a less prominent concentration profile. Consequently, this speeds up the cooling process and enhances the surface’s durability and strength.

Unsteady Free Convection MHD Flow over a Vertical Cone in Porous Media with Variable Heat and Mass Flux in Presence of Chemical Reaction

This paper investigated unsteady free convection MHD flow over a vertical cone in porous media with variable heat and mass flux in presence of chemical reaction. Appropriate non-dimensional variables are used to reduce the dimensional governing equations that consists of continuity, momentum, energy, and concentration equations along with imposed initial and boundary conditions. The purpose of the study is to investigate this unsteady MHD flow problem using Crank-Nicolson method. The discretization equations were computed, and numerical results were plotted using MATLAB software. Numerical Results for the velocity, temperature and concentration profiles are presented graphically and discussed for different values of the physical parameters to show interesting features of the solutions. The result showed that the velocity profile increases when porosity and buoyancy ratio parameters are escalated, while an opposite behavior is notice against magnetic parameter and chemical reaction parameter.

Thermophoresis and Brownian diffusion of nanoparticles around a vertical cone in a porous media by Galerkin finite element method (GFEM)

In this study, Galerkin weighted residual Finite Element Method is used to find the thermophoresis and Brownian diffusion motion of two phase nanofluid flow around a vertical cone in porous media. Gravity, Drag, Thermophoresis and Brownian forces are confided on the nanoparticles to find their motion during the time. The problem is solved in both transient and steady conditions. The effect of Nc and Nv parameters on the temperature and velocity profiles are investigated. Also, the effect of boundary conditions on the temperature and nanoparticles concentrations are investigated through the graphical contours. As a main result, variable thermal conductivity parameter (Nc) increament from zero to unity increased the velocity and temperature profile values, while had not significant effect on the nanoparticles concentration. Also, results revealed that increasing the Nv (from 2 to 200) and Nc (from 0 to 1), increased the (−θ′(0)) and (−f′(0)) to 1.36% and 0.15%, respectively.

Soret and Dufour effects on unsteady mixed convection flow over a vertical cone in porous medium with non-uniform slot suction/injection

The aim of present analysis is to investigate the combined effects of Soret Dufour and chemical reaction on unsteady mixed convection flow over a vertical cone in porous medium with non-uniform slot suction/injection. It is assumed that the flow field is unsteady due to time dependent free stream velocity. The governing boundary layer equations are transformed into non-dimensional form by using a group of non-similarity transformations. The resulting non-dimensional partial differential equations were solved numerically using implicit finite difference scheme in combination with the quasi-linearization technique. The results are presented through graphs for various values of parameters involved in the problem. Velocity, temperature, concentration profiles as well as the local Nusselt and Sherwood numbers are discussed through graphs. Comparison with previously published literature is performed and an excellent agreement is obtained.

Influence of Uniform Blowing/Suction on the Free Convection of Non-Newtonian Fluids Over a Vertical Cone in Porous Media With Thermal Radiation and Soret/Dufour Effects: Uniform Wall Temperature/Uniform Wall Concentration

This work studies numerically the combined heat and mass transfer of uniform blowing/suction, non-Newtonian power-law fluid, and thermal radiation effects on free convection adjacent to a vertical cone within a porous medium in the presence of Soret/Dufour effects. The surface of the vertical cone has a uniform wall temperature and uniform wall concentration (UWT/UWC). The Rosseland diffusion approximation is employed to describe the radiative heat flux. A nonsimilarity analysis is performed, and the transformed governing equations are solved by Keller box method (KBM). The effects of these major parameters of the Dufour parameter, Soret parameter, Lewis number, buoyancy ratio, power-law index of the non-Newtonian fluids, blowing/suction parameter, and thermal radiation parameter on the heat and mass transfer characteristics have been carried out. In general, for the case of blowing, both the local Nusselt number and the local Sherwood number decrease. This trend reversed for suction of fluid. The physical aspects of the problem are discussed in detail.

Non-Darcy Natural Convection Boundary Layer Flow Over a Vertical Cone in Porous Media Saturated with a Nanofluid Containing Gyrotactic Microorganisms with a Convective Boundary Condition

Non-Darcy Natural Convection Boundary Layer Flow Over a Vertical Cone in Porous Media Saturated with a Nanofluid Containing Gyrotactic Microorganisms with a Convective Boundary Condition

Evaluation of the heat transfer rate increases in retention pools nuclear waste

In this paper, we have tried to find a solution for quick transfer of nuclear wastes from pools of cool water to dry stores to reduce the environmental concerns and financial cost of burying atomic waste. Therefore, the rate of heat transfer from atomic waste materials to the outer surface of the container should be increased. This can be achieved by covering the bottom of the pool space with conical fins (vertically) embedded in porous medium and allowing natural convection flow of Newtonian nanofluid upon it. In this research, we studied the rate of heat transfer by using such special space. In this study, Heat transfer boundary layer flow in Nano-fluidics shifting from a vertical cone in porous medium, two-dimensional, steady, incompressible and low speed flow have been considered and attempts have been made to obtain analytical solutions for it. The obtained nonlinear ordinary differential equation has been solved through homotopy analysis method (HAM), considering boundary conditions and Nusselt number. Also, Nusselt number, which is an important parameter in heat transfer, is calculated using the obtained analytical solution by HAM. A comparison of the obtained analytical solution with the numerical results represented a remarkable accuracy. The results also indicate that HAM can provide us with a convenient way to control and adjust the convergence region.

Natural convection boundary layer flow due to gyrotactic microorganisms about a vertical cone in porous media saturated by a nanofluid

The similarity solution for Darcy free convection about an isothermal vertical cone with fixed apex half angle, pointing downward in a nanofluid saturated porous medium, has been made. It is assumed that the medium contains gyrotactic microorganisms along with nanoparticles and the cone is subjected to concentration of nanoparticles and density of motile microorganisms. The effects of Brownian motion and thermophoresis are incorporated into the model for nanofluids. The governing partial differential equations are converted into nonlinear ordinary differential equations using unique similarity transformations. The effects of the governing parameters on the dimensionless quantities such as velocity, temperature, nanoparticle concentration, density of motile microorganisms, local Nusselt, local Sherwood and local density numbers for both nanoparticles, and motile microorganism density are explored. A comprehensive numerical computation is carried out for various values of the parameters that describe the flow characteristics.

Effects of nanoparticles diameter and concentration on natural convection of the Al2O3–water nanofluids considering variable thermal conductivity around a vertical cone in porous media

The effects of nanoparticles diameter and concentration on natural convection heat transfer of a nanofluid around a vertical cone embedded in a Darcy porous medium is theoretically investigated utilizing the drift-flux model. The thermal conductivity and the viscosity of the nanofluid are assumed as simultaneous functions of temperature and local volume fraction of nanoparticles using experimental correlations. In addition, the flux of nanoparticles on the surface of the cone is assumed to be zero. An efficient mathematical approach with a self-similar solution is utilized to theoretically analyze the boundary layer heat and mass transfer of an Al2O3–water nanofluid. The reduced system of ordinary differential equations are general and can be solved for any arbitrary functions of thermal conductivity and viscosity. The analysis of the nanofluid natural convection flow is accomplished for two cases of (i) Tw>T∞ and (ii) Tw<T∞. The results show that using nanoparticles would not (would) enhance the heat transfer from the cone for the case of a cone with a hot surface (cold surface). A decrease in the size of nanoparticles or an increase in the volume fraction of nanoparticles causes a decline in the heat transfer rate from the cone when the cone surface is hot. Finally, a comparison between the non-homogenous model (drift-flux model) and the homogenous model of nanofluids is performed. The results demonstrate that the drift-flux model tends to the homogeneous model as the size and volume fraction of nanoparticles increase.

Flow and heat transfer affected by variable properties of nanofluids in natural-convection over a vertical cone in porous media

This paper attempts to theoretically analyze the effects of nanoparticles concentration gradient on the natural convection boundary layer flow of nanofluids around a vertical cone placed in a porous medium. The slip of nanoparticles is because of the Brownian motion and thermophoresis forces. The viscosity and the thermal conductivity of nanofluid are considered as a function of local volume fraction of nanoparticles. Two mathematical processes are performed. The first step is the simplification of the governing partial differential equations using appropriate similarity variables. The second step is the numerical solution of the obtained ordinary differential equations. Furthermore, based on the Buongiorno’s model, the new definition of the reduced Nusselt and Sherwood numbers is presented in details. The results reveal that the reduced Nusselt number would increase with increase of viscosity parameter and decrease with an increase of thermal conductivity parameter.

Natural-convection heat and mass transfer from a vertical cone in porous media filled with nanofluids using the practical ranges of nanofluids thermo-physical properties

The present study aims to analyze the effects of Brownian motion and thermophoresis forces on the natural convection heat transfer of nanofluids around a vertical cone placed in a saturated porous medium. The range of non-dimensional parameters and the definition of two important parameters of heat and mass transfer are discussed. The results show that the range of Lewis number as well as Brownian motion and thermophoresis parameters and also the definition of the reduced Nusselt and Sherwood numbers, used in the previous analyses, should be reconsidered. In the present study, reasonable definitions of reduced Nusselt and Sherwood numbers have been proposed and discussed in details. In contrast with previous researches, the present results show that the heat transfer associated with migration of nanoparticles is negligible compared with heat conduction and convection mechanisms.

Soret and Dufour effects on natural convection boundary layer flow over a vertical cone in a porous medium with constant wall heat and mass fluxes

This work studies the Soret and Dufour effects on the boundary layer flow due to natural convection heat and mass transfer over a vertical cone in a fluid-saturated porous medium with constant wall heat and mass fluxes. A similarity analysis is performed, and the obtained similar equations are solved by the cubic spline collocation method. The effects of the Dufour parameter, Soret parameter, Lewis number, and buoyancy ratio on the heat and mass transfer characteristics have been studied. The local surface temperature tends to increase as the Dufour parameter is increased. The effect of the Dufour parameter on the local surface temperature becomes more significant as the Lewis number is increased. Moreover, an increase in the Soret parameter leads to an increase in the local surface concentration and a decrease in the local surface temperature.

Natural convection heat transfer of non-Newtonian fluids in porous media from a vertical cone under mixed thermal boundary conditions

This work studies the problem of the steady natural convection boundary layer flow over a downward-pointing vertical cone in porous media saturated with non-Newtonian power-law fluids under mixed thermal boundary conditions. A similarity analysis is performed, and the obtained similar equations are solved by cubic spline collocation method. The effects of the power-law viscosity index and the similarity exponent on the heat transfer characteristics under mixed thermal boundary conditions have been studied. Under mixed thermal boundary conditions, both the surface heat flux and the surface temperature are found to decrease when the power-law viscosity index of the non-Newtonian power-law fluid in porous media is increased. Moreover, an increase in the similarity exponent tends to increase the boundary layer thickness and thus decreases the surface heat flux under mixed thermal conditions. The generalized governing equations derived in this work can be applied to the cases of prescribed surface temperature and prescribed heat flux.