Effects of IT, EGR, and IAT on Combustion and Emissions in a Diesel Engine Fueled with Tung Oil-Based Biodiesel Blends.

This study examines the viability of using a 20% tung oil biodiesel blend (B20) in diesel engines by analyzing its combustion performance and emission characteristics. The research specifically explores how injection timing (IT), EGR rates, and intake air temperature (IAT) influence engine behavior when running on this alternative fuel. The findings show a direct link between peak cylinder pressure and earlier IT. The combustion duration (CA10-CA90) reached its maximum value of 25.4 °CA at 10 °CA BTDC, which was 2.8 °CA longer than that at 5 °CA BTDC. These results suggest the presence of an optimal IT window. While NO emissions rose with earlier injection, soot peaked at 10 °CA BTDC. Increasing EGR rates reduced the in-cylinder pressure and combustion duration. Under the impact results of EGR, the NO and soot emissions exhibit opposing trends. Rising IAT (353-383 K) maintained relatively stable in-cylinder pressures; it intensified combustion thermal intensity, concurrently improving stability but elevating both NO and soot emissions. These results provide key guidance for the performance optimization of tung oil-based biodiesel and environmental governance.