Cause of Exhaust Smoke and Its Reduction Methods in an HSDI Diesel Engine Under High-Speed and High-Load Conditions 2002-01-1160
The cause of the exhaust smoke and its reduction methods in a small DI Diesel engine with a small-orifice-diameter nozzle and common rail F.I.E. were investigated under high-speed and high-load condition, using both in-cylinder observations and Three-dimensional numerical analyses. The following points were clarified during this study.
At these conditions, fuel sprays are easily pushed away by a strong swirl, and immediately flow out to the squish area by a strong reverse squish. Therefore, the air in the cavity is not effectively used. Suppressing the airflow in a piston cavity, using such ideas as enlarging the piston cavity diameter or reducing the port swirl ratio, decreases the excessive outflow of the fuel-air mixture into the squish area, and allows the full use of air in the whole cavity. Hence, exhaust smoke is reduced.
Citation: Hotta, Y., Nakakita, K., Fuyuto, T., Inayoshi, M. et al., "Cause of Exhaust Smoke and Its Reduction Methods in an HSDI Diesel Engine Under High-Speed and High-Load Conditions," SAE Technical Paper 2002-01-1160, 2002, https://doi.org/10.4271/2002-01-1160. Download Citation