Abstract
Experiments were performed for turbulent premixed flames of CH_4/air/H_2/ mixtures at high pressure to investigate the effects of hydrogen addition on turbulent combustion characteristics. OH-PLIF measurements were conducted to determine the effective Lewis numbers, turbulent burning velocity, smallest scale of flame wrinkles, and local flame surface density. Results showed that the decrease in the effective Lewis number for hydrogen addition ratio of 0.1 is small and mean volume of the flame region and the smallest scale were not affected by H_2 addition. However, ST/SL slightly increased, corresponding to the increase in the flame surface density possibly due to the increase in the grows rate of the intrinsic flame instability.