振荡燃烧过程的同步测量方法

Methods for simultaneous measuring processes of combustion oscillations

关键词:  振荡燃烧  受迫振荡  自激振荡  相同步测量⁺  燃烧动力学

Key words:  Combustion oscillations  Forced oscillations combustion  Self-excited oscillation combustion  Phase-locked measurement⁺  Combustion dynamics

摘要:

振动燃烧是由非稳定燃烧放热和压力脉动互相耦合产生的系统振荡过程。振荡燃烧的研究方法之一是对自激振荡燃烧相互耦合过程进行研究,得到系统的闭环特性。另外还可以对燃烧系统施加特定的扰动以得到燃烧系统的开环特性。为了研究振荡燃烧的动态过程,需要实现不同物理量的同步测量。相同步方法能够实现压力脉动与燃烧放热率脉动的同步测量,确定二者间的周期变化关系。通过对两个不同振荡类型的实验台进行相同步测量,分析振荡燃烧过程中压力脉动与放热率脉动的相位关系,并讨论了相同步方法的误差,提出了不同实现方案。这些结果将有助于我们提高火焰测量的相同步技术的准确性。

Abstract:

Combustion oscillations were induced by coupling between unsteady heat release and pressure perturbations. One way to study combustion oscillations is to measure the coupling process of self-excited combustion oscillations and to obtain the close-loop characteristics of combustion system. Another way is to induce the forced oscillations on the combustion system and to get the open-loop characteristics of system. To study the dynamical process of combustion oscillations, the simultaneous measurements of fluid properties were needed. In this paper, phase-locked measurement was used on two types of test rigs. The relationship of phase between them was analyzed and the error of measurement was discussed. The work will help us to improve the phase-locked measurement accuracy in combustion stability studies.