Triggering, bypass transition and the effect of noise on a linearly stable thermoacoustic system
Triggering, bypass transition and the effect of noise on a linearly stable thermoacoustic system
复制标题
触发、旁路转换和噪声对线性稳定热声系统的影响
DOI：
10.1016/j.proci.2010.06.018
复制
发表时间：
2011
影响因子：
3.4
通讯作者：
Waugh I
中科院分区：
文献类型：
--
作者：
Waugh I
本文探讨了热声学中的触发与流体力学中的旁路向湍流转变之间的类比。尽管系统是线性稳定的，但通过这两种机制，微小的扰动会导致系统产生较大的自持续振荡。例如，它解释了为什么圆管流动(Hagen-Poiseuille流)会变成湍流，即使它的所有特征值在所有雷诺数下都是稳定的。在流体力学中，旁路转变涉及初始扰动的瞬时增长，这是由于稳定性算子的线性非正规性引起的，然后吸引到一系列不稳定的Navier-Stokes方程的周期解，然后排斥到完全湍流或重新分层。本文指出，热声学中的触发过程与此直接类似。在热声学中，线性化的稳定性算子也是非正规的，并且也会引起瞬时增长。然后，系统朝着控制方程的不稳定周期解演化，接着是向稳定周期解或零解的排斥。本文论证了在低频下具有较高幅度的初始扰动比在所有频率上具有相似幅度的扰动更能有效地触发自持续振荡。然后，本文探讨了不同类型的噪声对触发的影响。考虑了三种类型的噪声：粉色噪声(低频时幅度较大)、白噪声(所有频率上幅度相似)和蓝色噪声(高频时幅度较高)。施加不同幅度的噪声，既有短脉冲噪声，也有连续噪声。粉色噪声比白噪声和蓝色噪声更能有效地引发触发，这与论文第一部分的结果一致。综上所述，本文研究了热声学中的触发机制，并证明了某些类型的噪声比其他类型的噪声更有效地引起触发。
This paper explores the analogy between triggering in thermoacoustics and bypass transition to turbulence in hydrodynamics. These are both mechanisms through which a small perturbation causes a system to develop large self-sustained oscillations, despite the system being linearly stable. For example, it explains why round pipe flow (Hagen–Poiseuille flow) can become turbulent, even though all its eigenvalues are stable at all Reynolds numbers. In hydrodynamics, bypass transition involves transient growth of the initial perturbation, which arises due to linear non-normality of the stability operator, followed by attraction towards a series of unstable periodic solutions of the Navier–Stokes equations, followed by repulsion either to full turbulence or re-laminarization. This paper shows that the triggering process in thermoacoustics is directly analogous to this. In thermoacoustics, the linearized stability operator is also non-normal and also gives rise to transient growth. The system then evolves towards an unstable periodic solution of the governing equations, followed by repulsion either to a stable periodic solution or to the zero solution. This paper demonstrates that initial perturbations that have higher amplitudes at low frequencies are more effective at triggering self-sustained oscillations than perturbations that have similar amplitudes at all frequencies. This paper then explores the effect that different types of noise have on triggering. Three types of noise are considered: pink noise (higher amplitudes at low frequencies), white noise (similar amplitudes at all frequencies) and blue noise (higher amplitudes at high frequencies). Different amplitudes of noise are applied, both as short bursts and continuously. Pink noise is found to be more effective at causing triggering than white noise and blue noise, in line with the results found in the first part of the paper. In summary, this paper investigates the triggering mechanism in thermoacoustics and demonstrates that some types of noise cause triggering more effectively than others.
影响因子：
8.6
作者：
Skufca, JD;Yorke, JA;Eckhardt, B
通讯作者：
Eckhardt, B
背景噪声对燃烧器稳定性的影响
DOI：
--
发表时间：
2002
期刊：
影响因子：
--
作者：
T. Lieuwen;A. Banaszuk
通讯作者：
A. Banaszuk
影响因子：
2.5
作者：
V. Burnley;F. Culick
通讯作者：
F. Culick