May it Please Your Honor : Letters of Petition as Historical Evidence in an African Colonial Context

This paper presents some preliminary conclusions drawn from an ongoing project which aims to collect and collate letters of petitions in colonial Nigeria as primary source for historians and other scholars. The goal is to show the potential use of petitions as a foundation for gauging African reactions and responses to colonialism focusing on the petitions that emerged during the Second World War in colonial Eastern Nigeria. The paper is based on the collection of petitions located at the National Archives of Nigeria at Enugu written by people living in the rural and urban areas in colonial Eastern Nigeria during the Second World War. Mainly addressed to District Officers in Colonial Eastern Nigeria from within the region, they reflect the concerns of individuals and groups as they relate to the crisis engendered by the Second World War and the policies and controls imposed by officials to bolster the British war effort

Development of an explicit multigrid algorithm for quasi-three-dimensional viscous flows in turbo-machinery

A rapid quasi three-dimensional analysis was developed for blade-to-blade flows in turbomachinery. The analysis solves the unsteady Euler or thin layer Navier-Stokes equations in a body-fitted coordinate system. It accounts for the effects of rotation, radius change, and stream-surface thickness. The Baldwin-Lomax eddy-viscosity model is used for turbulent flows. The equations which are solved by a two-stage Runge-Kutta scheme made efficient by use of vectorization, a variable time-step, and a flux-based multigrid scheme, are described. A stability analysis is presented for the two-stage scheme. Results for a flat-plate model problem show the applicability of the method to axial, radial, and rotating geometries. Results for a centrifugal impeller and a radial diffuser show that the quasi three-dimensional viscous analysis can be a practical design tool

Efficient solution of the Euler and Navier-Stokes equations with a vectorized multiple-grid algorithm

A multiple-grid algorithm for use in efficiently obtaining steady solutions to the Euler and Navier-Stokes equations is presented. The convergence of the explicit MacCormack algorithm on a fine grid is accelerated by propagating transients from the domain using a sequence of successively coarser grids. Both the fine and coarse grid schemes are readily vectorizable. The combination of multiple-gridding and vectorization results in substantially reduced computational times for the numerical solution of a wide range of flow problems. Results are presented for subsonic, transonic, and supersonic inviscid flows and for subsonic attached and separated laminar viscous flows. Work reduction factors over a scalar, single-grid algorithm range as high as 76.8

Impact of Selected Rural Development Programmes on Poverty Alleviation in Ikwuano LGA, Abia State, Nigeria

Rural development is a veritable tool for fighting poverty and achieving economic prosperity at the grassroots level. The concept of rural development embraced by most countries connotes a process through which rural poverty is alleviated by sustained increases in the productivity and incomes of low – income workers and households. The major thrust of this study was to examine the impact of selected rural development programmes in Ikwuano Local Government Area of Abia State, Nigeria. The area under study was purposively selected because of its agricultural potential, high proportion of farmers as well as concentration of agricultural institutions. The selection of programmes for the study was impinged on their long years of existence. The study sought to determine the number of available rural development programmes with poverty alleviation objectives in the area; assess the extent of awareness and participation of rural people in the programmes; and examine the impact of the programmes on farmers’ income, farm size, production and productivity. Multi – stage random sampling method was employed in the selection of communities and respondents. A well-structured questionnaire was used to elicit responses on socio – economic characteristics and other relevant variables from a random sample of 160 respondents comprising beneficiaries and non-beneficiaries from Ikwuano local government of Abia state, Nigeria. The results showed that the rural development programmes which had poverty alleviation objectives impacted significantly on productivity and farm income at 5 percent level of probability. Awareness was perceptibly high while participation was more in Agricultural Development Programme (ADP), with an overwhelmingly percentage representation of about 79, than in others. Programme planners and implementers are therefore urged to intensify awareness creation among rural dwellers and adopt the use of community driven development approach (CDD) in the execution of rural development projects with poverty alleviation thrust. Government, at all levels, was advised to adopt price support policy that raises income of producers.Rural Development Programme, Poverty Alleviation

Finite element analysis of inviscid subsonic boattail flow

A finite element code for analysis of inviscid subsonic flows over arbitrary nonlifting planar or axisymmetric bodies is described. The code solves a novel primitive variable formulation of the coupled irrotationality and compressible continuity equations. Results for flow over a cylinder, a sphere, and a NACA 0012 airfoil verify the code. Computed subcritical flows over an axisymmetric boattailed afterbody compare well with finite difference results and experimental data. Interative coupling with an integral turbulent boundary layer code shows strong viscous effects on the inviscid flow. Improvements in code efficiency and extensions to transonic flows are discussed

Numerical analysis of three-dimensional viscous internal flows

A 3-D Navier-Stokes code has been developed for analysis of turbomachinery blade rows and other internal flows. The Navier-Stokes equations are written in a Cartesian coordinate system rotating about the x-axis, and then mapped to a general body-fitted coordinate system. Streamwise viscous terms are neglected using the thin-layer assumption, and turbulence effects are modeled using the Baldwin-Lomax turbulence model. The equations are discretized using finite differences on stacked C-type grids and are solved using a multistage Runge-Kutta algorithm with a spatially-varying time step and implicit residual smoothing. Calculations have been made of a horseshoe vortex formed in front of a flat plate with a round leading edge standing in a turbulent endwall boundary layer. Comparisons are made with experimental data taken by Eckerle and Langston for a circular cylinder under similar conditions. Computer and measured results are compared in terms of endwall flow visualization pictures and total pressure loss contours and vector plots on the symmetry plane. Calculated details of the primary vortex show excellent agreement with the experimental data. The calculations also show a small secondary vortex not seen experimentally

Comparison of two- and three-dimensional flow computations with laser anemometer measurements in a transonic compressor rotor

Two and three dimensional inviscid solutions for the flow in a transonic axial compressor rotor at design speed are compared with probe and laser anemometers measurements at near-stall and maximum-flow operating points. Experimental details of the laser anemometer system and computational details of the two dimensional axisymmetric code and three dimensional Euler code are described. Comparisons are made between relative Mach number and flow angle contours, shock location, and shock strength. A procedure for using an efficient axisymmetric code to generate downstream pressure input for computationally expensive Euler codes is discussed. A film supplement shows the calculations of the two operating points with the time-marching Euler code