⎯ this research investigates the optimal buoy shape for a conceptual point absorber Wave Energy Converter (WEC) for harnessing low amplitude sea waves characteristic of the Gulf of Guinea coast. It has been established that shape of buoy is one of the main parameter affecting the efficiency of a point absorber WEC. Based on best buoy shapes as reported in literature, two shapes are selected for comparison: cone-cylinder composite buoy and Concave wedge shaped buoy. The WEC's buoy and the power take off were mathematically modelled as a mass-spring-damper system. The buoys hydrodynamic coefficients were computed using strip theory, while the simulation in the time domain was executed using MATLAB. Impute parameters referred to as the sea states, in five levels, were described by the significant wave height Hs and the corresponding energy period Te, typical of the gulf. Output parameters are displacement, velocity, acceleration and force of the buoys, as well as the instantaneous power output of the WEC. For the levels considered, the optimum sea state for the two buoys peaked at level 4 (Hs = 1.5 m, Te = 14 s), with concave wedge buoy having an optimal power output of 8 kW while that of cone-cylinder being 3.7 kW. For the other levels the wedge buoy also consistently gives relatively greater power output than the cone cylinder buoy.

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This paper presents the results from experimental validation of numerical simulation of a concept wave energy converter for low amplitude sea waves. The device was conceived to contain a wave amplifying device (WAD) to magnify the wave height of incident waves while point absorber buoy(s) efficiently harness the wave energy for electricity production. The validation results show that the optimum aperture angle for the WAD is 45±2 degree, and wave height magnification of 170% is possible. The optimal buoy shape for the device was confirmed as concave wedge buoy. The combination of the two in a single device shall make economical the harnessing of low amplitude waves.

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Separation theory describing the motions of palm kernel and shell on rotating incline was analysed. Two series of differential equations, in order to obtain the dispatch angles of kernel and shell for the separation process were developed respectively. The differences in the motions and physical features of the particles formed the premise for separation. The results obtained from the theory showed a possibility of product separation within the approximate ranges of dispatch angles between 25 and 90 0 for kernels and shells on rotating incline, with specified slide limit, angular velocity and radius of the incline, and comparisons were made between the theoretical and experimental results. The dispatch angles obtained from both theory and experiment reasonably showed significant agreement and therefore suggested validity of the developed theory.