Exhaust Purification of Diesel Engines by Homogeneous Charge with Compression Ignition Part 2: Analysis of Combustion Phenomena and NOx Formation by Numerical Simulation with Experiment

An experimental and a numerical analysis wereconducted based on the concept of homogeneous charge diesel combustion (HCDC), in which most of the fuel is supplied for pre-mixed homogeneous charge which is compressed in the cylinder and then ignited by small amount of diesel fuel directly injected into a cylinder.

At the previous report, It was indicated that simultaneous improvement of NOx and smoke were possible. Especially under a certain condition, NOx was extremely reduced.

This report describes the preliminary analysis for the cause of this emission improvement with HCDC method.

As result, direct optical observation of the combustion phenomena and numerical analysis using KIVA2 code suggested that low NOx combustion may be caused by lowered combustion temperature and reduced combustion period due to the uniform lean combustion.