Browsing by Author "Bennett, Kevin Frank"

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    Energy utilisation in South Africa.
    (1977) Bennett, Kevin Frank; Dutkiewicz, Ryszard Karol
    The purpose of this study is to provide the Department of Planning and the Environment with the following information: 1) The quantities and forms of input and useful energy used by different sectors of the South African economy. (The terms input energy and useful energy are defined in section 1.2 of this chapter). 2) The efficiency of conversion of input energy to useful energy. 3) Current and expected trends in energy utilization within individual sectors of the economy.The two year contract to carry out this study was awarded to the Energy Research Institute at the University of Cape Town. The work was undertaken by one engineer assisted by a graduate engineer, supported by secretarial staff and supervised by a professor of the Department of Mechanical Engineering.
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    Energy utilization in the domestic sectors.
    (1979) Stone, Andrew John; Dutkiewicz, Ryszard Karol; Bennett, Kevin Frank
    In South Africa the domestic sector is an important energy user. Information is available on how much energy is supplied to this sector but little is known about how this energy is utilized. The purpose of this thesis is to try and gather information on this area of domestic energy utilization. As the domestic sector is made up of a large number of mall users a selected sample of the users is needed to provide information which is representative of the sector as a whole. A postal survey was used to gather information from a representative sector of the White community. This method was unsuitable for the Black sector but information on Black household energy usage was obtained from a Department of Health report. With the use of a postal survey of a sample group to estimate results for the sector as a whole, inaccurate results will occur unless the sample is truly representative of the sector. To ensure this, independent figures for the income per household and the number of urban and rural households were obtained and the sample results weighted accordingly.
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    An estimation of the performance of spark ignition methanol engines
    (1981) Yates, Andrew David Bennett; Dutkiewicz, Ryszard Karol; Bennett, Kevin Frank
    The possibility of using methanol as an alternative fuel for petrol and diesel engines has been investigated at the University of Cape Town in recent years by the Energy Research Institute. Engines, taken from existing road vehicles, were converted to methanol operation and evaluated. During the planning phase of each conversion, it was apparent that there was a need for a method of estimating the probable performance of the converted engine. The objective of this thesis was therefore to develop a generally applicable formula for predicting the rated performance of a methanol-fuelled, spark-ignition engine given only the bore, stroke, number of cylinders and maximum rated engine speed. The prediction was based on an estimate of the indicated efficiency, the volumetric efficiency and the frictional losses of a methanol engine, from which the shaft power and overall efficiency could be determined. The performance of three engines, which were converted to methanol operation, was used to test the theory. The conversions were each of a very different nature: - a) An automotive petrol engine of which only the carburettor was modified. b) An automotive petrol engine that was modified to take advantage of the properties of methanol to improve the performance. c) A truck diesel engine that was converted to spark ignition for operation on methanol. The predicted results were found to compare favourably with the experimental results, with the exception of one spurious reading. An analysis of the range of error in the theoretical estimate was used as the basis for comparison: Range of error in predicted overall efficiency ± 6%. Range of error in predicted shaft power ± 10%. The work of this thesis would be applicable in situations where a quick answer was required and few details were available. With the aid of a programmable calculator, the anticipated performance map could be obtained in a few minutes.