Browsing by Author "Adegoke, J. A"

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Contemporary aspects of Monte Carlo methods and simulation in physics
(Faculty of Science, University of Abuja, 2004) Olowofela, J. A; Adegoke, J. A; Adewumi, O. P; Kamiyole, I. C.
"This article introduces Monte Carlo methods which are different from conventional numerical methods and show how some of the methods can be applied in Physics to stimulate or solve physical problems, through computer programmes (written in FORTRAN in this case) by using a few examples touching modern and classical physics showing its usefulness. A functional approach to probability and statistics is described for the purpose of this work instead of complete treatment. The importance of good sequence of random numbers with large periods is demonstrated and the methods, in same instance are compared with conventional type and differences pointed out. "
Effect of porosity on surface of drawndown in an unsteady state drainage in porous material. I
(2007) Olowofela, J. A .; Adegoke, J. A; Bejide, F. A.; Okeyode, I. C.
"This work considered the unsteady state drainage of fluid from a vertical column of porous material of varying porosities in an attempt to verify variation of drawndawn surface with porosity and time using riverbed sand. Kerosene was used as the flowing fluid. Mathematical assumptions ware made in connection with Darcy's law. The result showed that the experiment which was designed from the theoretical framework agreed with the theory to a large extent, However, this is not in perfect agreement with an earlier experiment which was performed using well rounded beads in which glycerine was used as the flowing fluid. A FORTRAN program was written to study the variation theoretically and this was compared with the experimental result. There exists, a degree of discrepancy between theory and experiment indicating that, the mathematical formulations did not perfectly agree with the complex earth system as compared with the bead model that was initially used. There is a need for the modification of the mathematical formulations; nonetheless, an unsteady drawndown, pattern was attained with different porosity even in medium with very complex geometry. "
Modification of Darcy's law for turbulent flow in saturated porous media
(Medwell, 2007) Popoola, O. I.; Adegoke, J. A; Alabi, O.
"Darcy's law is an essential equation in determining the permeability of porous media which is vital tool in seepage and drainage control in soils. However, whenever the aggregate sizes of the porous media and hydraulic gradient are large, the flow in drains will be semi-turbulent to turbulent. This research aims at modifying the true Darcy's permeability determined under small hydraulic gradients that ensure laminar or nearly laminar flow to allow for reduced efficiency caused by turbulence at greater hydraulic gradient and provide a relation between the maximum gradient for laminar flow and porosity of the porous media. A modeled experiment was set up using sand samples of different porosities from riverbed as porous media, which were packed in a vertical transparent cylinder tube of diameter 1.85x102m and relative permeabilities were determined for gradient ranging from 1.15-15.00. The result of the experiment shows that relative permeability increases with increasing porosity but decreases with increasing gradient. The maximum (or limiting) hydraulic gradient for laminar flow decreases with increasing porosity. Also, the vertical fluid flow in any porous medium is laminar or nearly laminar as much as hydraulic gradient is less than or equal to 1.04. "