轴向旋流器单通道甲烷/空气回火特征大涡模拟研究

LES Study on Flashback of Single Channel of an Axial Swirler for Premixed CH4/Air Mixture

关键词:  贫预混燃烧  旋流叶片  通道  回火  大涡模拟

Key words:  Lean premix combustion  Swirler vane  Channel  Flashback  Large eddy simulation

摘要:

为了研究轴向旋流器叶片单通道间的回火特征，采用大涡模拟方法对旋流器叶片吸力面侧和压力面侧点火后火焰面的发展过程进行了比较研究。结果表明:纯流动下，吸力面侧有回流区，压力面侧无回流区；吸力面侧点火后，火焰面随吸力面侧的回流区向上游发展；压力面侧点火后，压力面侧不会回火，但是会引燃吸力面侧，进而回到吸力面侧回火模式；火焰面传递的关键位置为内壁面或叶片尾缘。

Abstract:

In order to study the characteristics of flashback in one channel of an axial swirler，large eddy simulation was used to compare the developing process of flame front after ignition near the suction surface and the pressure surface. Based on the results ，the following conclusions are obtained. Firstly，backflow zone only exists near the suction surface in the case without reaction.Secondly，after ignition near the suction surface，the flame front propagates along the backflow zone. Finally，after ignition near the pressure surface，even though flashback cannot take place near the pressure zone，the flame front can spread to the suction zone and it returns to the position of ignition near the suction zone. The key location for the transition is in the trailing edge or the inner wall.