Insights of Transitions to Thermoacoustic Instability in Inverse Diffusion Flame using Multifractal Detrended Fluctuation Analysis

TL;DR

This paper investigates the dynamical transitions leading to thermoacoustic instability in inverse diffusion flames using multifractal analysis, revealing loss of multifractality as a key indicator of instability onset.

Contribution

It introduces the use of multifractal detrended fluctuation analysis to characterize and classify the transition to instability in inverse diffusion flames.

Findings

Loss of multifractality near instability region

Singularity exponent and Hurst exponent as reliable indicators

Multifractal spectrum width as a classifier

Abstract

The inverse diffusion flame (IDF) can experience thermoacoustic instability due to variations in power input or flow conditions. However, the dynamical transitions in IDF that lead to this instability when altering control parameters have not been thoroughly investigated. In this study, we explore the control parameters through two different approaches and employ multifractal detrended fluctuation analysis to characterize the transitions observed prior to the onset of thermoacoustic instability in the inverse diffusion flame. Our findings reveal a loss of multifractality near the region associated with thermoacoustic instability, which suggests a more ordered behavior. We determine that the singularity exponent, the width of the multifractal spectrum, and the Hurst exponent are reliable indicators of thermoacoustic instability and serve as effective classifiers of dynamical states in inverse diffusion flames.