MST-Department of Mathematics

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Browsing MST-Department of Mathematics by Subject "Analysis"

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    Analysis of Heat and Mass Transfer on Magnetohydrodynamics (Mhd) Nanofluids with Thermal Radiation and Brownian Motion Over A Heated Vertical Plate
    (Kenyatta University, 2019-04) Ndungu, Elizabeth Wambui
    This study investigates the effect of heat and mass transfer on Magnetohydrodynamics (MHD) nanofluid with thermal radiation and brownian motion over a heated vertical plate. The Magnetohydrodynamics (MHD) nanofluid flow have different electrical conductivities and behave differently in presence of thermal radiation, magnetic field, thermophoresis and brownian motion. The rate of heat and mass transfer on nanofluid along the vertical plate under the influence of a magnetic field with thermal radiation and Brownian motion leads to change in the fluid motion. The diverse applications of nanofluids in engineering and industries it is of this great importance hence the need to investigate the effects of thermal radiation, thermophoresis and Brownian motion on nanofluids and magneto hydrodynamics. Nanofluids are considered as potential working fluids to be used in high heat flux systems such as electronic cooling systems, solar applications, heat pipes, and nuclear reactors. As secondary fluids, they can be applied in commercial refrigeration, chiller and solar panels in absorption systems. They provide much more energy for a given weight of fuel than any technology in use , at the same time reducing thermal pollution. The governing non-linear boundary layer equations are formulated and transformed into ordinary differential equations using the similarity transformation. The resulting ordinary differential equations are solved numerically using the fourth order Runge-Kutta method. The numerical results for dimensionless parameters as well as the skin-friction coefficient and nusselt number, are presented graphically and analysed quantitatively. We note that increasing magnetic field, radiation, thermophoresis and Brownian motion parameters leads to an increase in the fluid temperature resulting in a reduction in the Nusselt number and Sherwood number
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    Analysis of Magnetohydrodynamic Convective Heat Transfer of Casson Nanofluid Flow Over a Heated Stretching Vertical Plate
    (Kenyatta University, 2022) Kigio, John Kinyanjui; Winifred Nduku Mutuku
    Casson fluid has many industrial and engineering applications. However, Casson nanofluid possesses superior electrical and thermal conductivities compared with the original Casson fluid. Hence, the Casson nanofluid is considered in this project. The equation governing the natural convective magnetohydrodynamics flow of Casson nanofluid across a a convectively heated vertical plate is formulated. The equation is reformulated into a system of ordinary differential equations (ODEs) using similarity transformations. Thereafter, a numerical solution of the resulting ODEs is obtained using the Runge-Kutta-Gills method. It is found that flow temperature profiles increase with increasing Eckert number, Biot number and magnetic field strength while flow velocity decreases as the flow becomes Newtonian and as nanoparticle volume fraction increases.
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    Analysis of Magnetohydrodynamic Stagnation Point Flow Due to a Fluid towards a Convectively Heated Permeable Stretching Sheet
    (Kenyatta University, 2020-10) Mwangi, Njoroge Kelvin
    Stagnation-point flow of an electrically conducting fluid over a continuously stretching surface in presence of magnetic fields is significant in many industrial processes such as the metallurgy, polymer processing, glass blowing, filaments drawn through quiescent electrically conducting fluid subject to magnetic fields, cooling of metallic plate, hot rolling, wire drawing, aerodynamic extrusion of plastic sheets, crystal growing. In these applications of stagnation point flow, the desired output depends largely on the rate of heating and the velocity of the fluid on the surface. The required rate will be achieved by variation of various thermophysical parameters such as suction parameter, Grashoff number, Hartmann number and buoyancy parameter. The resulting nonlinear partial differential equations governing this flow were reduced to nonlinear ordinary differential equations using similarity transformations and the resulting equations solved numerically using the fourth order Runge-Kutta scheme with a shooting technique. Graphical results were presented and discussed quantatively with respect to the effects of thermophysical parameters on both velocity and temperature profiles of the fluid. From the study we note that an increase in Grashoff number (Gr), Hartmann number (Ha) and suction parameter resulted to a corresponding increase in fluid velocity. The fluid temperature also increased with increase in Gr and Ha but decreased with increase in suction parameter and buoyancy parameter.