Numerical Investigation of the Effects of Rate-Shaped Main Injection on Combustion and Emission in an OPOC Two-Stroke Diesel Engine

The effects of various split injection strategies on the opposed-piston opposed-cylinder (OPOC)diesel engine combustion and emission characteristics have been studied numerically using AVL-Fire CFD tools. The five rate-shaped main injections were used in split injection strategies. The results show that ignition delay from a rectangular injection rate is the shortest. Maximum pressure of the trapezoid injection rate is the largest. And the NO_x emission of the rectangular injection rate is the largest. Meanwhile, the soot emission of the trapezoid injection rate is the least among the five injection rates.