Master Theses and Dissertations(MST)http://ir-library.ku.ac.ke/handle/123456789/1592021-03-04T05:39:49Z2021-03-04T05:39:49ZAnalysis of Heat and Mass Transfer on Magnetohydrodynamics (Mhd) Nanofluids with Thermal Radiation and Brownian Motion Over A Heated Vertical PlateNdungu, Elizabeth Wambuihttp://ir-library.ku.ac.ke/handle/123456789/217402021-03-04T00:07:58Z2019-04-01T00:00:00ZAnalysis of Heat and Mass Transfer on Magnetohydrodynamics (Mhd) Nanofluids with Thermal Radiation and Brownian Motion Over A Heated Vertical Plate
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
A research project submitted in partial fulfillment of the requirements for the award of the degree of Master of Science in applied mathematics in the school of pure and applied sciences of Kenyatta University. April 2019
2019-04-01T00:00:00ZAction of Symmetric Group S5 on The Cosets of Some of Its Non-Maximal SubgroupsOmori, Kerubo Lydiahhttp://ir-library.ku.ac.ke/handle/123456789/217392021-03-04T00:05:08Z2020-07-01T00:00:00ZAction of Symmetric Group S5 on The Cosets of Some of Its Non-Maximal Subgroups
Omori, Kerubo Lydiah
A research project submitted in partial fufillment of the requirements for the award of the Master of Science in Pure Mathematics in the School of Pure and Applied Sciences of Kenyatta University. July, 2020
2020-07-01T00:00:00ZInvestigating Turbulent Convection in a Rectangular Enclosure Using Shear Stress Transport K-Ω ModelMuhoro, John Nyagahttp://ir-library.ku.ac.ke/handle/123456789/217382021-03-04T00:08:52Z2020-01-01T00:00:00ZInvestigating Turbulent Convection in a Rectangular Enclosure Using Shear Stress Transport K-Ω Model
Muhoro, John Nyaga
Studies have been done on the aspect ratio effect on natural convection turbulence using standard
k-ε model but further studies showed that k-ω SST model performed better than both k-ε and k-ω
model in the whole enclosure. Thus, there was need to do a numerical study on the natural
convection fluid flow in a rectangular enclosure full of air using SST k-ω model. The left vertical
wall of the enclosure was maintained at a steady high temperature Th of 323K while the right wall
at a steady cool temperature Tc of 303K with the remaining walls adiabatic. Time-averaged energy,
momentum and continuity equations with the two equation SST k-omega turbulence model were
used to generate isotherms, streamlines and velocity magnitudes for different aspect ratios of the
enclosure so as to be able to investigate effect of aspect ratio on turbulence. It was shown that as
the aspect ratio of increased from 2, 4, 6 and 8 of the enclosure, the velocity of elements decreased
and the vortices became smaller and more parallel thus concluded that an increase in aspect ratio
decreased the turbulence.
A Project Submitted in Partial Fulfillment of the Requirements for
the Award of Degree of Masters of Science in Applied Mathematics in
the School of Pure and Applied Sciences
Of
Kenyatta University
2020-01-01T00:00:00ZA Numerical Study of Turbulent Natural Convection in a Rectangular Enclosure with Localised Heating and CoolingMutua, Clementine K.http://ir-library.ku.ac.ke/handle/123456789/217372021-03-04T00:06:13Z2019-08-01T00:00:00ZA Numerical Study of Turbulent Natural Convection in a Rectangular Enclosure with Localised Heating and Cooling
Mutua, Clementine K.
This study models natural turbulent convection in a rectangular enclosure with localized heating and cooling. The equations used in modeling the flow are the equation of continuity, momentum equation and the energy equation. These equations are decomposed using the Reynolds decomposition then the decomposed equations are non – dimensionalised and reduced using the Boussinesq assumptions. The model that is considered is a rectangular enclosure with one side wall being heated and the other side wall being cooled. The other walls of the enclosure are adiabatic. The non – linear differential equations obtained by using the k - 𝜀 turbulence model are solved using the finite difference technique and a computer program called FLUENT 6.3.26 is used in the presentation of results in form of contours. The results of the study show that with increase in the Rayleigh Number, there is increase in the number of contours and vortices. With regard to the velocity magnitude, it is found that an increase in the Rayleigh number results in increase in the turbulence hence implying that there is an increase in the velocity magnitude.
A Research Project Submitted in Partial Fulfillment of the Requirements for the Award of the Degree of Master of Science in Applied Mathematics in the School of Pure and Applied Sciences of Kenyatta University. August, 2019
2019-08-01T00:00:00Z