Abstract
The purpose of this study is to investigate the effects of the mean cylinder temperature and pressure from the start of injection to ignition on ignition delay period in a D.I. diesel engine, and to clarify the difference in the ignition delay period between the engine and a constant volume bomb. The ignition delay period in the engine was measured by changing the following factors such as injection timing, engine speed, swirl ratio, injection quantity, nozzle opening pressure, nozzle hole diameter and piston cavity shape. The cylinder temperature was measured by a fine thermocou-ple with a compensation circuit under the motored condition. A single shot injection was adopted to reduce the residual gas from a previous cycle. Results are as follows:
Ignition delay period in the engine can be arranged with the cylinder temperature and pressure. The engine shows shorter ignition delay than the constant volume bomb. The difference in the ignition delay between them is mainly due to the existance of the piston cavity wall on which the fuel spray impinges.
