DEPENDENCE OF MAGNETICALLY INDUCED CHANGE IN OH DISTRIBUTION IN A METHANE-AIR PREMIXED FLAME ON EQUIVALENCE RATIO

摘要

In order to explore the possibility of combustion control by magnetic field. the magnetically induced change in the spatial distribution of OH radicals in a methane-air premixed flame was visualized via planar laser-induced fluorescence measurements. Then equivalence ratio was changed from 0.89 to 1.8 under a constant total flow rate. The results clearly showed that the change in OH fluorescence intensity distribution depended on the equivalence ratio. At equivalence ratios smaller than 1.0 (fuel-lean conditions), the OH concentration was decreased in the downstream region of the flame by the magnetic field, while it was increased in the upstream region. At ratios greater than 1.0 (fuel-rich conditions), the decrease region existed in the peripheral region of the flame, while the increase region was inside the (lame. The change rate of the OH distribution tended to become larger as the equivalence ratio became larger. The mechanisms of these phenomena were discussed in conjunction with O_2 flows induced magnetically.