抄録
To understand the combustion process in a spark ignition engine with an unscavenged horizontal prechamber, the flame propagation in both the pre- and main chamber is simultaneously visualized by a high speed camera changing the torch nozzle area, while keeping the engine speed of N≅1000rpm, the volumetric efficiency of ηv≅80% and the air-fuel ratio of A/F≅15 constant. Then an image-processing camera is used to assign the brightness of flame photograph into 16 steps of false color, and the signals of brightness are stored in floppy disk of computer through an image memory (or slot card). Such image-processed flame patterns are projected on the T.V. display and possible to be taken photograph by a still- or 8mm camera.
Accordingly, it is seen that the patterns of flame propagation in the main chamber are remarkably affected by torch nozzle area and the ratio of burned portion to main chamber area (combustion area fraction) is also similar to the engine output (BMEP). Furthermore the time history of averaged brightness distribution on the center line of the main chamber is found to be in reasonable agreement with the time history of combustion gas temperature on the same line measured by an infrared pyrometer.
