管壁熱傳對預混火焰的影響

• Main Authors: Hsu, Sheng-Yen, 許聖彥
• Other Authors: 李石頓
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/77422379991981301543

碩士 === 國立臺灣大學 === 機械工程學研究所 === 90 === Effects of wall on the premixed fuel-lean flame in cylindrical tube are investigated numerically in this study. In this study, in addition to the axisymmetric flow assumption, a simplified four-step mechanism is employed to model the chemical reaction. The computational results show that the higher the wall-temperature is, the stronger the effect on the flame propagation of the action of wall on the radical becomes. The effects on the flame propagation are also investigated of (1) wall thickness, (2) heat transfer coefficient for the outer wall, (3) the flame-wall relative velocity, (4) wall conductivity and (5) wall thermal diffusivity. Results show that the thicker the wall thickness, the larger the heat transfer coefficient, wall-flame relative velocity and the wall thermal conductivity, the smaller the wall thermal diffusivity are, the lower the wall-temperature and the flame propagation speed become, resulting in mushroom flame; otherwise, the wall temperature and flame speed increase, resulting in the tulip-flame.