LPP燃烧室燃烧不稳定特征三维模拟
Three-dimensional simulation of combustion instability characteristics in LPP combustor
李昊 1刘勇 1张祥 1王旭怀 1杨晨 1刘重阳2
作者信息
- 1. 南京航空航天大学 能源与动力学院,南京 210016
- 2. 西北工业大学 动力与能源学院,西安 710072;中国航发四川燃气涡轮研究院,四川绵阳 621000
- 折叠
摘要
为分析贫油预混预蒸发(LPP)燃烧室的燃烧不稳定(CI)特征,通过对三维亥姆霍兹方程进行了三种不同程度的简化:平均温度场和导入CFD温度场的无源项方程,以及导入燃烧流场特征的有源项方程,分别对单头部LPP燃烧室模型进行了三维频域特征数值仿真.结果表明:燃烧室内的温度分布是燃烧室声学特征频率的重要影响因素,释热率源项对主频无影响.相比于仅设置平均温度场,导入CFD三维温度场可以获得与实验频率更吻合的结果,精度提高了 5％.采用解耦方式求解频域方程能够快速建立声学系统与燃烧流场间的联系,释热率和迟滞时间的空间分布特征表现在亥姆霍兹方程的源项,其对预测燃烧室固有频率没有影响,但是能够获得详细声压分布特征.
Abstract
In order to analyze the combustion instability(CI)characteristics of lean premixed pre-vaporized(LPP)combustor,three-dimensional Helmholtz equations were simplified at three different levels.The average temperature field equation without source term,the imported CFD temperature field equation without source term,and the imported combustion flow field characteristics equation with source term,were respectively simulated for the single-head LPP combustor model in three-dimensional frequency domain.The results showed that the temperature distribution in the combustor was an important factor affecting the acoustic eigenfrequency of the combustor,and the source term of heat release rate had no effect on the main frequency.Compared with only setting of average temperature field,importing the 3D temperature field calculated by CFD can obtain more consistent results with the experimental frequency,and the accuracy was increased by 5％.The relationship between the acoustic system and the combustion flow field can be quickly established by solving the frequency domain equation in a decoupling way.The spatial distribution characteristics of heat release rate and hysteresis time were represented by the source term of the Helmholtz equation,which had no effect on the prediction of the natural frequency of the combustion chamber,but the detailed sound pressure distribution characteristics can be obtained.
关键词
贫油预混预蒸发(LPP)燃烧室/声学特征频率/燃烧不稳定(CI)/声学有限元计算/热声耦合Key words
lean premixed pre-vaporized(LPP)combustor/acoustic eigenfrequency/combustion instability(CI)/finite element calculation/thermal acoustic coupling引用本文复制引用
基金项目
中国航发自主创新专项(ZZCX-2019-009)
出版年
2024
NETL
NSTL
万方数据