In order to simplify the modeling process of flame transfer function,the calculation model of delay time and gain was studied by using random sampling and optimization method based on the experimental data.Firstly,the low order thermoacoustic network(LOTAN)model of lean premixing prevaporizing(LPP)model combustor test system was established.Then,based on the LOTAN model and test data,Sobol sampling was used to construct the sampling space of n-τ.Finally,n-τ was reconstructed based on the Kriging model.The results showed that the flame transfer function constructed based on this method can accurately express the unsteady heat release characteristics under various working conditions;if being substituted into LOTAN,the predicted results of oscillation frequency were in good agreement with the experimental results,the maximum error did not exceed 5%,at the same time,the critical fuel air ratio(FAR)predicted by this method was consistent with the experimental results.
关键词
不稳定燃烧/低阶热声网络模型/火焰传递函数/n-τ模型/Sobol采样
Key words
unstable combustion/low order thermoacoustic network model/flame transfer function/n-τ model/Sobol sampling