| Abstract: | An experimental study is conducted to investigate the fuel-injection-pressure and engine-speed effects on the performance and exhaust emissions of a naturally aspirated four-stroke indirect-injection (IDI) diesel engine with a swirl combustion chamber. The influence of the injection pressure and the engine rotational speed on fuel consumption, exhaust-gas temperature, exhaust smokiness and exhaust-gas emissions (nitrogen oxides and unburned hydrocarbons) is examined, following a detailed experimental investigation. Empirical easy-to-use correlations are produced, expressing the variation of the various parameters with injection pressure, by applying a regression analysis on the curves fitting the relevant experimental data. Theoretical aspects of diesel fuel spray progress (atomization, evaporation and mixing), combustion and emissions formation are used for the interpretation of the observed engine behaviour. |
