画像処理によるディーゼル火炎の解析

抄録

A picture processing technique is applied to study the flame motion in a direct-injection diesel engine. From the high-speed photographs, two-dimensional cross-correlation coefficients of flame luminosity between two successive frames are obtained. The location and value of the maximum coefficients give us the mean and fluctuating velocities of the flame, respectively. The results show that the fluctuating velocity obtained in a wide region is almost independent of measuring position and size in the middle and later stages of combustion, indicating that the turbulent flow field is almost uniform and isotropic over the space. Furthermore, the effects of the swirl and chamber geometry on the flame behavior are discussed in detail.