高温升燃烧室热声耦合特性研究

Thermoacoustic coupling characteristics of high temperature rise combustor

关键词:  高温升燃烧室  不稳定燃烧  低阶热声网络模型  热声稳定性  火焰传递函数

Key words:  High temperature rise combustor  Unstable combustion  Low order thermoacoustic network model  Thermo-acoustic stability  Flame transfer function

摘要:

为建立燃烧室热声不稳定性预测和分析方法，以某高温升单管燃烧室试验件为研究对象，构建了试验系统低阶热声网络（LOTAN）模型。基于试验数据，利用优化的方法获得了各工况下的火焰传递函数（FTF），并利用Kriging模型拟合出了增益与迟滞时间对工况参数的响应模型。利用拟合出的FTF响应模型分析了油气比和进气速度对燃烧室热声稳定性的影响。研究结果表明：通过优化得到的FTF能够较准确反映各工况下的非稳态热释放特性，导入LOTAN中计算得到的结果与试验结果吻合较好，最大误差约3.32%；油气比的改变会引起不稳定模态的转变，油气比或进气速度升高时，系统特征频率也随之升高。

Abstract:

In order to develop a prediction and analysis method of thermoacoustic instability for combustor， one can test rig of high temperature rise combustor was secleted as research object， and the low order thermoacoustic network （LOTAN） model of test system was constructed. Based on the experimental data， the parameters of flame transfer function （FTF） under various working conditions were obtained by optimization method， and the response model of gain and hysteresis time to working conditions parameters is fitted by Kriging model. The effects of fuel-air ratio（FAR） and intake speed on the thermoacoustic stability of the combustion chamber were analyzed by using the fitted FTF response model. The results show that the optimized FTF can accurately reflect the unsteady heat release characteristics under various working conditions， and the calculated results imported into LOTAN are in good agreement with the experimental results， the maximum error is about 3.32%. The change of FAR can cause the transformation of unstable mode. When the FAR or intake speed increases， the characteristic frequency of the system also increases.