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Intake valve deposits (IVD) and combustion chamber deposits (CCD) in spark-ignition engines greatly affect nitrogen oxides (NOx) emission and octane requirement increases (ORI) as they prevent the heat release from the combustion chamber and increase the compression ratio. Currently, fuel performance additives to control IVD and CCD have been attracted and evaluation method based on CCD weight and thickness has been widely used. However, simple measurement of the CCD weight and thickness does not clearly reflect the CCD effect on the ORI, as the shape and location of the deposits are also crucial factors that must be considered along with the weight and thickness of the deposits. In this paper, an ORI engine test procedure using a 4 cylinder 2.0 liter SOHC engine is introduced.

A component based approach to the design and implementation of distributed control systems for automotive engine manufacturing machines is described in this paper. The research is being undertaken in collaboration with the In-Line and Diesel Engine (IL&DE) division of the Ford Motor Company and several of its leading machine builders. The approach offers significant advantages over traditional methods. The external drivers of change affecting the automotive manufacturing sector are reviewed and the need for a better solution to the design and implementation of control systems is explained within this context. Existing best practise for the implementation of control systems for automotive engine manufacturing machinery is described. The new approach supports the implementation fully distributed control systems where a centralised PLC or PC based controller is not required and the control logic is embedded into the components of the machine.

A method to enable the impact of a novel component based approach to the implementation of production machinery design and build processes from the perspectives of the manufacturing engineering partners within the automotive industry is reported in this paper. The assessment method is based upon the representation (using CIMOSA based constructs) and simulation (using the ithinktm software package) of the activity, actor and event relationships between distributed partners when involved in a global engine manufacture programme. Assessment is vital to ensure that the impact of any novel approach is appreciated in terms and metrics that are consistent with the current operational and interaction paradigms. Without this information is it extremely difficult for the engineering partners to appreciate the impact of changes on their roles, responsibilities and profits and hence determine a roadmap and timescale for the adoption of the changes associated with the novel technology.

A new diffusing-oriented spray stratified combustion system for direct injection gasoline engines is proposed in this study. A reflector with multi-impingement wall head attached ahead of multi-hole injector nozzle is used in this system as a strategy of breaking up the fuel spray and directing it in a desired direction to form a perfect atomization and stratification of fuel air mixture. A comparatively rich fuel-air mixture is always formed over a wide range of engine operation conditions in the vicinity of spark plug due to the fuel spray oriented by the special surface shape of impingement wall, and the finely atomized fuel spray is formed in the other areas of combustion chamber due to the impacting of fuel spray against the impingement wall. Therefore, it is possible to achieve stable and fast burn of lean fuel air mixture. The combustion system is preliminary investigated on a single cylinder four-stroke DI gasoline engine which is shifted from a DI diesel engine.

The effect of various intake compositions and intake pressure on combustion & emission characteristics has been investigated in a single cylinder direct injection diesel engine. The variation of intake composition is simulated using argon, nitrogen and carbon dioxide as intake air diluents, and a screw compressor is used to boost intake pressure up to 200KPa. All diluents are found to be effective in reducing NOx emissions when intake pressure is changed from 110KPa to 200Kpa. Smoke emissions are drastically increased by the addition of argon, moderately increased by the addition of nitrogen. However, the addition of carbon dioxide substantially reduces smoke emissions and NOx emissions simultaneously. At lower intake pressure, the effects of diluting intake air with argon, nitrogen and carbon dioxide on ignition delay are proportional to their specific heats respectively, whereas the addition of argon has almost no effect on ignition delay when intake pressure is higher than 150KPa.

A multizone phenomenological combustion model, in which the fuel bum rate is governed by the rate of fuel vaporization and mixing, is developed to study the effects of split injection schemes on NO and soot emissions of direct injection diesel engines. This model is calibrated with the experimental data of a single injection case. Comparison between the results calculated by the model and experimental results shows that the model has a good predictive capability for cylinder pressure, heat release rate, NO & soot emissions. The study of split injection parameters, including the delay dwell between injection pulses, the fuel quantity injected in the second pulse and the fuel pressure of the second injection, is carried out. The results predicted by the model show that the soot can be effectively reduced without increasing NO emission and fuel consumption with the split injection in which 10-30% of total fuel is injected in the second injection at about 15 °CA after top dead center.