基于白噪声信号的旋流预混火焰传递函数的数值模拟

Numerical Simulation of Flame Transfer Function of Swirl Premixed Flame Based on White Noise Signal

利用2种不同的宽频噪声信号对旋流预混火焰进行扰动,并比较二者的频谱特性,利用经典的比例控制环节验证传递函数程序的准确性;通过不同位置速度脉动之间的传递函数,以及火焰热释放与速度脉动之间的火焰传递函数验证了计算结果的准确性。结果表明:2种信号的火焰传递函数基本重合,且具有明显的对流特性,对流涡与火焰之间的相互作用是导致热释放波动的内在机理;幅频特性表现出了明显的低通特性,相频特性满足比例关系,研究对于燃烧室设计具有重要的实际工程应用价值。

The vortex premixed flame was disturbed by two different broadband noise signals and their spectral characteristics were compared.The accuracy of the transfer function program was verified by the classical proportional control link.Meanwhile,the accuracy of the calculation results was verified by the transfer functions between the velocity pulsations at different positions and the flame transfer function between flame heat release and velocity pulsation.Results show that the flame transfer functions of the two signals basically coincide with each other and have obvious convective characteristics.The interaction between convective vortex and flame is the internal mechanism leading to heat release fluctuation.The amplitude-frequency characteristics show obvious low-pass characteristics,and the phase-frequency characteristics meet the proportional relationship.The research has important engineering application value for the combustion chamber design.