微小重力環境を利用した火炎振動現象の研究

摘要

本研究では，外部ふく射加熱によって生じる火炎振動伝播現象を通常重力環境下および微小重力環境下で観察した.得られた結果を以下にまとめる.(1)微小重力環境下においても振動伝播現象が観察されたことから，本実験で観察された振動現象の主要な発生要因は重力に起因する不安定性ではないと言える.しかし，重力の有無で振動周期や伝播速度などに明確な違いが生じることから，振動伝播現象に対する重力の影響を無視することはできない.%Effect of external radiation on flame propagation phenomena of ethylene premixed gas was investigated. The mixture is charged in the combustion tube of 50mm in diameter at 0.1MPa and C0_2 laser was irradiated along the centerline of the tube. With this configuration it was found that oscillatory flame propagation appeared in some gas mixture conditions. The flame oscillation pattern was influenced by the component of gas mixture and gravitational condition. It was suggested that this phenomena is caused by the transformation of flame front curvature by locally increased flame speed, which closely relates with thermal-diffusive flame instability in combination with flame stretch effect.