Noraihan Afiqah Rawi

Mixed convection flow of viscoelastic fluid over a sphere under convective boundary condition embedded in porous medium

The investigation on mixed convection boundary layer of a viscoelastic fluid over a sphere which is embedded in porous medium under convective boundary condition is carried out in this paper. The boundary layer equations of viscoelastic fluid are an order higher than Newtonian (viscous) fluid and the adherence boundary conditions are insufficient to determine the solution of these equations completely. Hence, the augmentation on extra boundary conditions is needed in order to solve this problem. The governing partial differential equations are first transformed into non-dimensional forms and then solved numerically using the Keller-box method by augmenting extra boundary conditions at infinity. The numerical results obtained for limiting case are comparing with related outcomes in order to validate the present results. Results on the effects of the viscoelastic parameter in the presence of porosity and mixed convection on the skin friction and heat transfer as well as velocity and temperature profile have been discussed.

Effect of gravity modulation on mixed convection flow of second grade fluid with different shapes of nanoparticles

The problem of unsteady mixed convection flow of second grade fluid over an inclined stretching plate under the influence of different shapes of nanoparticles is studied in this paper. The influence of gravity modulation is also considered. Carboxymethyl cellulose solution (CMC) is chosen as the non-Newtonian base fluid. Based on Tiwari-Das nanofluid model, the governing partial differential equations are transformed into a system of ordinary differential equations and solved numerically using an implicit finite difference scheme. The effect of different shapes and volume fraction of solid nanoparticles on the enhancement of convective heat transfer of second grade nanofluid associated with the effect amplitude of modulation, frequency of oscillation, and material parameter is discussed in details. The results indicated that, the needle-shaped nanoparticles give the highest enhancement on the heat transfer of second grade nanofluid compared to sphere and disk-shaped nanoparticles.

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.

Unsteady mixed convection flow of Casson fluid past an inclined stretching sheet in the presence of nanoparticles

The influence of nanoparticles on the unsteady mixed convection flow of Casson fluid past an inclined stretching sheet is investigated in this paper. The effect of gravity modulation on the flow is also considered. Carboxymethyl cellulose solution (CMC) is chosen as the base fluid and copper as nanoparticles. The basic governing nonlinear partial differential equations are transformed using appropriate similarity transformation and solved numerically using an implicit finite difference scheme by means of the Keller-box method. The effect of nanoparticles volume fraction together with the effect of inclination angle and Casson parameter on the enhancement of heat transfer of Casson nanofluid is discussed in details. The velocity and temperature profiles as well as the skin friction coefficient and the Nusselt number are presented and analyzed.

g-Jitter induced mixed convection flow and heat transfer of micropolar nanofluids flow over an inclined stretching sheet

g-Jitter induced mixed convection flow of micropolar nanofluids past an inclined stretching sheet is numerically studied in this paper. Copper (Cu) in water based is considered. The governing partial differential equation is transformed into non-dimensional form by using appropriate non-dimensional variables and then solved by using Keller-box method. The behaviour of physical quantities such as skin friction and heat transfer coefficients as well as the velocity, microrotation and temperature profiles are investigated for both strong and weak concentration of microelements. The numerical results show that, the values of reduced skin friction and heat transfer coefficient are increased by increasing the material parameter but produce an opposite behaviour with the increasing in nanoparticles volume fraction parameter.

g-Jitter induced MHD mixed convection flow of nanofluids past a vertical stretching sheet

The unsteady two dimensional convective boundary layer flow of nanofluids past a vertical permeable stretching sheet associated with the effect of g-jitter is studied in this paper. Two different types of water based nanofluids are considered which are copper (Cu) and aluminium oxide (Al2O3). The governing boundary layer equations in the form of partial differential equations are transformed into nonlinear coupled ordinary differential equations and solved numerically using an implicit finite-difference scheme known as the Keller-box method. The effects of amplitude of modulation, frequency of oscillation and solid nanoparticle volume fraction parameters on the reduced skin friction and Nusselt number are presented and discussed. An excellent agreement was observed between the current and earlier published results for some special cases. Numerical results show that, the values of reduced skin friction increase with the increasing of solid nanoparticle volume fraction but produce the opposite behaviour for the values of heat transfer coefficient.

G-Jitter Induced MHD Mixed Convection Flow Past an Inclined Stretching Sheet

This paper studies the effect of periodical gravity modulation, or g-jitter induced magnetohydrodynamics (MHD) mixed convection flow past an inclined stretching sheet. Using appropriate non-dimensional variables, the governing partial differential equations are first transformed into non-dimensional form. The obtained non-dimensional equations are then solved numerically using Keller-box method. The features of the flow with heat transfer characteristics for different values of frequency, amplitude and magnetic parameters on the velocity and temperature profiles are analyzed and discussed. The behaviour of physical quantities such as skin friction and heat transfer coefficients are also investigated. To validate the present numerical results, comparison with published results is done and found to be in a good agreement.

The effect of g-jitter on double diffusion by mixed convection past an inclined stretching sheet

In this paper, the effect of g-jitter on double diffusion by mixed convection past an inclined stretching sheet is studied. The velocity, concentration and temperature of the sheet are assumed to vary linearly with x, where x is the distance along the sheet. The resulting non-similar boundary layer equations are solved numerically using an implicit finite-difference scheme. Numerical results on the flow and heat and mass transfer characteristics are presented graphically for different values of amplitude, buoyancy ratio parameter and inclination angle. Results show that rate of heat and mass transfers increase but reduced skin friction decreases as the angle of inclination increases. It is noted that as buoyancy ratio parameter increases, rate of heat and mass transfer as well as reduced skin friction are decreases.