Sharidan Shafie

Effect of heat generation on free convection boundary layer flow of a viscoelastic fluid past a horizontal circular cylinder with constant surface heat flux

Effect of heat generation on free convection boundary layer flow of a viscoelastic fluid past a horizontal circular cylinder with constant surface heat flux has been investigated. The boundary layer equations are an order higher than those for the Newtonian (viscous) fluid and the adherence boundary conditions are insufficient to determine the solution of these equations completely. The governing equations are transformed into dimensionless non-similar equations by using a set of suitable transformations and solved numerically by the finite difference method along with Newtons linearization approximation. Computations are performed numerically by using Keller-box method by augmenting an extra boundary condition at infinity. We have focused our attention on the evaluation of velocity profiles, temperature profiles, shear stress in terms of local skin friction and the rate of heat transfer in terms of local Nusselt number for different values of heat generation parameter, viscoelastic parameter and the Prandlt number and the numerical results have been shown graphically.

Molybdenum disulfide nanoparticles suspended in water-based nanofluids with mixed convection and flow inside a channel filled with saturated porous medium

The shape effect of molybdenum disulfide nanoparticles suspended in water-based nanofluids with mixed convection flow inside a channel filled with saturated porous medium is studied. The radiation effect is also considered. One of the boundary walls of the channel is oscillating in its own plane. Four different shapes (platelet, blade, cylinder, and brick) of molybdenum disulfide nanoparticles inside a water, chosen as a conventional base fluid are used. The partial differential equations governed the problem are solved analytically by using perturbation method. Solutions for velocity and temperature are obtained and discussed graphically. A comparison of different shapes of molybdenum disulfide nanoparticles is analyzed. Results show that, nanoparticles with platelet and cylinder shapes have the highest thermal conductivity and viscosity compared to blade and brick shapes.

The effects of heat generation or absorption on MHD stagnation point of Jeffrey fluid

The analysis on the problem of heat generation/absorption effects on MHD stagnation point of Jeffrey Fluid is carried out. The governing partial differential equations are first transform as first order ordinary differential equation using similarity transformation before solving using numerical scheme called Keller-box. A comparative study with the previous results is made in order to verify the validation of the present results. The results for the skin friction and heat transfer coefficient as well as velocity and temperature profiles are presented and discussed in details for various values of heat generation/absorption parameter, magnetic parameter, Deborah number and Prandtl number.

Unsteady Mixed Convection Boundary Layer Flow past a Sphere in a Micropolar Fluid

The unsteady mixed convection flow over a sphere in a micropolar fluid is studied. The unsteadiness is due to an impulsive motion of the free stream. The governing boundary layer equations are first reduced into a non-dimensional form. The nondimensional equations are transformed into a set of non-similarity boundary layer equations. The solutions are obtained numerically using an efficient implicit finite-difference method known as the Keller-Box method. The algorithm for 3D Keller-Box method has been developed. The numerical results obtained are presented through tables and graphs. The results show that the parameters such as material, microrotation and mixed convection parameters for assisting and opposing cases have strong influence on the fluid motion.

Magnetohydrodynamic flow of dusty fluid past a vertical stretching sheet with Hall effect

The investigation on hydromagnetic flow of dusty fluid with Hall effect over a vertical surface of stretching sheet has been conducted. The governing partial differential equations are transformed into ordinary differential equations by using similarity transformation. The resulting differential equations are solved numerically by using Runge Kutta Fehlberg forth-fifth method (RKF45 Method). The effects of magnetic parameter, fluid-particle interaction parameter, Grashof number and Hall parameter on velocity and temperature profiles are presented graphically. The numerical values of the velocity gradient and wall temperature gradient are also shown in a tabular form.

Unsteady magnetohydrodynamics mixed convection flow in a rotating medium with double diffusion

Exact solutions of an unsteady Magnetohydrodynamics (MHD) flow over an impulsively started vertical plate in a rotating medium are presented. The effects of thermal radiative and thermal diffusion on the fluid flow are also considered. The governing equations are modelled and solved for velocity, temperature and concentration using Laplace transforms technique. Expressions of velocity, temperature and concentration profiles are obtained and their numerical results are presented graphically. Skin friction, Sherwood number and Nusselt number are also computed and presented in tabular forms. The determined solutions can generate a large class of solutions as special cases corresponding to different motions with technical relevance. The results obtained herein may be used to verify the validation of obtained numerical solutions for more complicated fluid flow problems.

MHD forced convective flow past a vertical plate: An automated solution approach

The forced convection flow in incompressible viscous fluid past a vertical plate is investigated with the effect of magnetic field. The governing equations are solved numerically using automated solution technique which is FEniCS. It is shown that the increasing of magnetic field strength lead to decrease the velocity but increase the temperature for cooled plate. Meanwhile for heated plate, increasing magnetic field strength lead to decrease the velocity and the temperature of the fluid.The forced convection flow in incompressible viscous fluid past a vertical plate is investigated with the effect of magnetic field. The governing equations are solved numerically using automated solution technique which is FEniCS. It is shown that the increasing of magnetic field strength lead to decrease the velocity but increase the temperature for cooled plate. Meanwhile for heated plate, increasing magnetic field strength lead to decrease the velocity and the temperature of the fluid.

Mixed convection boundary layer flow of viscoelastic nanofluid past a horizontal circular cylinder: Case of constant heat flux

The steady of two-dimensional convection boundary layer flow of a viscoelastic nanofluid over a circular cylinder is investigated in this paper. Carboxymethyl cellulose solution (CMC) is chosen as the base fluid and copper as a nanoparticle with the Prandtl number Pr = 6.2. The governing boundary layer partial differential equations are transformed into dimensionless forms. Then they are solved numerically by using the Keller-Box method. This paper focus on the effects of selected parameter on the flow and heat transfer characteristics and be presented in graphs. The results show that, the velocity profiles and the temperature profiles are increased by increasing the values of nanoparticles volume fraction. While velocity profile decreases when viscoelastic parameter is increase. The reverse trend is observed for the temperature profiles. Also, the values of reduced skin friction are increased by increasing mixed convection parameter, but the values of heat transfer coefficient produce an opposite behaviour with an increasing in mixed convection parameter.

Magnetohydrodynamics effect on convective boundary layer flow and heat transfer of viscoelastic micropolar fluid past a sphere

The main interest of this study is to investigate the effect of MHD on the boundary layer flow and heat transfer of viscoelastic micropolar fluid. Governing equations are transformed into dimensionless form in order to reduce their complexity. Then, the stream function is applied to the dimensionless equations to produce partial differential equations which are then solved numerically using the Keller-box method in Fortran programming. The numerical results are compared to published study to ensure the reliability of present results. The effects of selected physical parameters such as the viscoelastic parameter, K, micropolar parameter, κ and magnetic parameter, M on the flow and heat transfer are discussed and presented in tabular and graphical form. The findings from this study will be of critical importance in the fields of medicine, chemical as well as industrial processes where magnetic field is involved.

Exact solutions for unsteady free convection flow of carbon nanotubes over an oscillating vertical plate

The purpose of this paper is to study the unsteady convection flow of carbon nanotubes (CNTs) induced by free convection with oscillating plate condition. Single-wall CNTs are used with water as base fluids. The governing partial differential equations and boundary conditions are transformed into a set of ordinary differential equations using suitable dimensionless variables. These equations are solved analytically using Laplace transform technique to obtain the velocity and temperature profiles. Results for velocity and temperature are shown in various graphs and discussed for the embedded flow parameters in detail. It is observed that, velocity decreases with increasing CNTs volume fraction and an increase in CNTs volume fraction increases the nanofluid temperature, which leads to an increase in the heat transfer rates.