热声耦合燃烧振荡中火焰锋面识别分析

Analysis of Flame Front Identification in Thermo-acoustic Coupled Combustion Oscillation

针对火焰图像中火焰锋面位置难以确定的问题,通过自行开发MATLAB程序和恒定强度阈值算法对图像中的火焰锋面边界进行识别和优化,对图像的二值图进行形态学处理,获得时域内火焰锋面的归一化面积曲线;利用Labview程序实现高速照相机、光电倍增管和麦克风的同步触发,结合频谱信息得到相同周期内的归一化面积脉动和热释放率脉动。分析后显示,两者变化趋势基本相同,皮尔逊相关系数为0.915,为极强相关关系,验证了此方法的可行性。

It is difficult to determine the position of flame front in the flame images.The self-developed MATLAB program and constant intensity threshold algorithm were used to identify and optimize the flame front boundary in the images.The binary diagram plot of images was morphologically processed to obtain the normalized area curve of the flame front in time domain.Labview program was used to achieve synchronous triggering of high-speed camera,photomultiplier and microphone.Combined with the spectrum information,the normalized area pulsation and heat release rate pulsation within the same period were obtained.The analysis shows that the change trend of the two is basically the same,and Pearson correlation coefficient is 0.915,which is a very strong correlation.The feasibility of this method is verified.