钝体改进结构对先进旋涡燃烧室燃烧流动特性影响

Influence of improved structure of bluff-body on combustion flow characteristics in advanced vortex combustor

为探究先进旋涡燃烧室凹腔稳焰机制,提出了一种后钝体结构改进方案,并对改进后的燃烧室燃烧特性进行了预混和非预混燃烧数值模拟.结果表明:预混燃烧条件下,当量比为0.6和1.0时,钝体改进结构可有效增强凹腔内旋涡流动强度,增加凹腔内温度,同时使温度分布更加均匀.另外,凹腔内温度随预混进气速度增加而增加,且当速度增大到一定值时,温度变化不明显;非预混燃烧条件下,钝体改进结构可改善凹腔内旋涡流动及温度分布,在贫油燃烧状态时,凹腔内仍可维持较高的温度;钝体改进使燃烧室质量更小,具有一定的工程参考意义.

In order to study the mechanism of flame stabilization in cavity of advanced vortex combustor,an improvement program of after bluff-body structure was introduced,and the combustion characteristics of improved combustor under the conditions of premixed and non-premixed combustion were numerically simulated.The results show that under the condition of premixed combustion,the improved bluff-body structure can enhance the intensity and temperature of vortex flow in cavity,and make the temperature distribution more evenly no matter if equivalence ratio is 0.6 or equal to 1.0.In addition,the cavity temperature increases with the increasing premixed inlet velocity,and changes little when the velocity reaches a certain value.Under the condition of non-premixed combustion,the improved bluff-body structure ameliorates the vortex flow and temperature distribution in cavity,and the cavity maintains relatively high temperature under the condition of lean burning.The improved lightweight combustor can provide certain reference for engineering application.