An investigation on the effects of late intake valve closing and exhaust gas recirculation in a single-cylinder research diesel engine in the low-load condition

TLDR: In this article, the effects of late intake valve closing and exhaust gas recirculation on the emissions and engine performance of a single-cylinder diesel research engine were observed using two cam profiles (symmetric and asymmetric) implemented using an offset angle at various injection valve closing timings to characterize the engine performance and the emissions.

Abstract: The effects of late intake valve closing and exhaust gas recirculation on the emissions and the engine performance of a single-cylinder diesel research engine were observed. Two cam profiles (symmetric and asymmetric) were implemented using an offset angle at various intake valve closing timings to characterize the engine performance and the emissions. The injection timings were swept at every condition to evaluate the optimal operating conditions. The highest indicated mean effective pressure was observed once the combustion phasing was tuned to the optimum crank angle (in degrees) by varying the injection timing. The indicated mean effective pressure exhibited a slight penalty when both exhaust gas recirculation and late intake valve closing were used in comparison with the base intake valve closing timing with no exhaust gas recirculation. However, an appropriate combination of the exhaust gas recirculation with late intake valve closing was effective in reducing the nitrogen oxide emissions owing to t...