摘要
利用OH平面激光诱导荧光技术测量CH4/H2/空气预混湍流火焰前锋面结构,得到湍流燃烧速率.采用不同孔径和开孔比的湍流发生板,产生不同湍流强度和尺度下稳定的预混湍流火焰供OH-PLIF测量.利用500张瞬时火焰结构图片得到湍流火焰前锋面的平均位置,运用角度法得到湍流燃烧速率.分析了掺氢比和湍流强度对湍流燃烧速率的影响,并给出了拟合关系式.实验结果表明,湍流燃烧速率随湍流强度的增加而增加,这是由于流场尺度减小引起火焰锋面面积增加.湍流燃烧速率随掺氢比的升高略有增加,这是由于掺氢引起火焰不稳定性增强,导致火焰对湍流流动的响应增强,增强了湍流火焰前锋面褶皱,从而增加了火焰面面积.湍流燃烧速率可以表示为ST/SL∝a(u′/SL)n,其中指数n约为0.35.
Instantaneous flame front structure and turbulent burning velocities of CH4/H2/air mixtures were measured using OH-PLIF technique. Various turbulence intensities were generated by perforated plates with different hole diameter and opening ratio. Stabilized turbulent premixed flames were obtained at the outlet of the Bunsen burner for long-duration OH-PLIF measurement. 500 single shot images were averaged to obtain turbulent burning velocity by conventional angel method. The effects of hydrogen addition and turbulence intensity on turbulent burning velocity were analyzed and a power law correlation of turbulent burning velocity was obtained. Results show that turbulent burning velocity increases with the increase of turbulence intensity due to the increase of flame front area. Hydrogen addition increases the flame intrinsic instability and leads to the active response of laminar flame to turbulence, resulting in the much wrinkle flame front structure, larger flame front area and subsequently the increased turbulent burning velocity. A correlation between turbulent burning velocity and turbulence intensity was derived in the form of ST/SL∝ma（U＇/SL）^n and n remained a constant value of 0.35.
出处
《燃烧科学与技术》
EI
CAS
CSCD
北大核心
2013年第6期512-516,共5页
Journal of Combustion Science and Technology
基金
国家自然科学基金资助项目(51006080
51376004)
中央高校基本科研业务费专项资金资助项目
