Comparisons of Combustion Characteristics of Biodiesels in a High Speed Direct Injection Diesel Engine

A modified KIVA code is used to simulate the operation of a small bore HSDI engine with biodiesel from various sources. Genetic modified soybean biodiesel has very similarly combustion characteristics with soybean biodiesel, albeit less NO_x. Yellow grease biodiesel burns in a similar manner as regular diesel with less NO_x. All types of biodiesel show longer ignition delay but faster combustion, except after TDC injection, where biodiesel exhibits some diffusion combustion. Delaying injection is an effective way to reduce NO_x emission. Over 90% of reduction in NO_x is observed when fuel injection is delayed from 335° to 363°.