الفهرس 
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Abstract
ABSTRACT
There is a great need for a power system for naval submarines that can fill the energy gap between the low performance conventional diesel electric battery system and the high performance nuclear reactor base plant. This is because the submerged endurance time is of a fatal importance in submarine effectiveness.
In addition to many other potential applications, the closed cycle diesel engine systems (CCDEs), provides straight forward and economic solution to fill this gap. The engine, then, has to make use of synthetic atmosphere of oxygen and managed exhaust gases as a working fluid whose thermodynamic properties approach those of air.
The interrelationships between the non-air oxidants with moderate gases for synthetic atmosphere and engine performance are note documented or understood or mostly overlooked while developing the complete closed cycle diesel engine with the associated exhaust management problems. The present work was established, therefore, with the overall objective of delineating, assessing, and determining the theoretical and experimental performance of diesel engine when operating on non-air mixtures based on using nitrogen as a top up gas.
The complexity of the combustion process under synthetic atmosphere with the uncertainties associated with the mixing, kinetics of reaction (physical and chemical delays), non-equilibrium effects and heat release data as well as the heat transfer data, etc., would have made using the presently developed actual cycle computer models, practically impossible to be justified, at least, until adequate data becomes available.
A theoretical model based on the fueVsynthetic atmosphere cycle approximation for the diesel engine was developed. This necessitates the construction of temperature-entropy charts for both the synthetic atmosphere and the corresponding combustion gases. The charts and diesel engine cycle allocations are programmed with sufficient generality to represent any synthetic atmosphere constituents concentrations and under different excess synthetic atmosphere factors.
An experimental rig, including a single cylinder diesel engine, a synthetic atmosphere metering apparatus and all the required instruments, was designed, constructed and, employed to provide results for comparison with the theoretical model.
The deteriorating performance effects of C02 percentage increase by volume lmder constant 02 content of 21 % and 30 % by volume respectively are determined. Also the beneficial effects of increasing O2
percentage by volume for constant C02 contamination of 35 % by volume are also analyzed. The differences between maintaining O2 constant at 21 % by volume and at 23.3 % by mass and increasing the C02 percentage by volume are also shown.
It is shown that the performance of the diesel engine near full load and under synthetic atmosphere operation can beneficially exceed its normal air operation counterpart. Volumetric C02 intake concentration below 24 % appear to have little effect on performance of indirect injection diesel engine. However, the diesel engine could not operate beyond 25% C02
by volume until the O2 percentage increase to 25% by volume where the engine is adequately able to be run with C02 percentage increase by volume up to 28%.
The theoretical model results, based on the fueVsynthetic atmosphere cycle approximation, showed fairly satisfactory agreement with the experimental results and/or the previous works.