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We present a phenomenological reduced-order model to capture the transition to thermoacoustic instability in turbulent combustors. The model is based on the framework of synchronization and considers the acoustic field and the unsteady heat…

Adaptation and Self-Organizing Systems · Physics 2022-06-14 Yue Weng , Vishnu R. Unni , R. I. Sujith , Abhishek Saha

Open-loop control is known to be an effective strategy for controlling self-excited thermoacoustic oscillations in turbulent combustors. In this study, we investigate the suppression of thermoacoustic instability in a lean premixed,…

Thermoacoustic instability in turbulent combustion systems emerges from the complex interplay among the flame, flow, and acoustic subsystems. While the onset of thermoacoustic instability exhibits global order in system dynamics, the…

Fluid Dynamics · Physics 2023-08-01 Samadhan A. Pawar , P. R. Midhun , K. V. Reeja , Abin Krishnan , Krishna Manoj , R. I. Sujith

We, herein, present a new model based on the framework of synchronization to describe a thermoacoustic system and capture the multiple bifurcations that such a system undergoes. Instead of applying flame describing function to depict the…

Adaptation and Self-Organizing Systems · Physics 2020-06-11 Yue Weng , Vishnu R. Unni , R. I. Sujith , Abhishek Saha

The synchronization phenomena in thermoacoustic systems leading to oscillatory instability can effectively be modeled using Kuramoto oscillators. Such models consider the nonlinear response of flame as an ensemble of Kuramoto phase…

Chaotic Dynamics · Physics 2025-02-20 Rohan K. Nakade , Samarjeet Singh , Jayesh M. Dhadphale , R. I. Sujith

In reacting flow systems, thermoacoustic instability characterized by high amplitude pressure fluctuations, is driven by a positive coupling between the unsteady heat release rate and the acoustic field of the combustor. When the underlying…

Fluid Dynamics · Physics 2022-02-16 Jayesh Dhadphale , Vishnu R. Unni , Abhishek Saha , R. I. Sujith

Abrupt transitions to the state of thermoacoustic instability (TAI) in gas turbine combustors are a significant challenge plaguing the development of next-generation low-emission aircraft and power generation engines. In this paper, we…

Fluid Dynamics · Physics 2022-12-21 Ramesh S. Bhavi , Induja Pavithran , Amitesh Roy , R. I. Sujith

We investigate flame-acoustic interactions in a turbulent combustor during the state of intermittency before the onset of thermoacoustic instability using complex networks. Experiments are performed in a turbulent bluff-body stabilized dump…

This paper presents an experimental study of the influence of heat losses on the onset of thermoacoustic instabilities in methane-air premixed flames propagating in a horizontal tube of small diameter, $D = 10$ mm. Flames are ignited at the…

In this experimental study on a laboratory-scale turbulent annular combustor with sixteen swirl-stabilized burners, we study the flame-flame and flame-acoustic interactions during different dynamical states associated with the longitudinal…

Fluid Dynamics · Physics 2021-01-11 Amitesh Roy , Samarjeet Singh , Asalatha Nair , Swetaprovo Chaudhuri , R I Sujith

The occurrence of abrupt dynamical transitions in the macroscopic state of a system has received growing attention. We present experimental evidence for abrupt transition via explosive synchronization in a real-world complex system, namely…

Fluid Dynamics · Physics 2023-09-18 Amal Joseph , Induja Pavithran , R. I. Sujith

The onset of thermoacoustic instabilities in lean-premixed gas-turbine combustors is a crucial problem leading to degradation in engine and emissions performance and shortened component life. The main aim of this study is to propose a…

Data Analysis, Statistics and Probability · Physics 2007-05-23 G. Gianni , G. Mariotti , E. Paganini , S. Sello

Thermoacoustic instabilities in gas turbines and aeroengine combustors falls within the category of complex systems. They can be described phenomenologically using nonlinear stochastic differential equations, which constitute the grounds…

Fluid Dynamics · Physics 2016-12-09 Edouard Boujo , Alexey Denisov , Bruno Schuermans , Nicolas Noiray

Rocket engine combustors are prone to transverse instabilities that are characterized by large amplitude high frequency oscillations in the acoustic pressure and the heat release rate. We study the coupled interaction between the acoustic…

Fluid Dynamics · Physics 2022-05-25 Praveen Kasthuri , Samadhan A. Pawar , Rohan Gejji , William Anderson , R. I. Sujith

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…

Turbulent reacting flows confined to ducts are plagued by thermoacoustic instability, a state in which a positive feedback between flow, flame and acoustic perturbations leads to the emergence of catastrophically high-amplitude oscillatory…

A non-isothermal phase field model that captures both displacive and diffusive phase transformations in a unified framework is presented. The model is developed in a formal thermodynamic setting, which provides guidance on admissible…

Materials Science · Physics 2011-12-02 Mirko Maraldi , Garth N. Wells , Luisa Molari

We report the occurrence of amplitude death (AD) of limit cycle oscillations in a bluff body stabilized turbulent combustor through delayed acoustic self-feedback. Such feedback control is achieved by coupling the acoustic field of the…

Hydrodynamic modes in the turbulent mixing layer over a cavity can constructively interact with the acoustic modes of that cavity and lead to aeroacoustic instabilities. The resulting limit cycles can cause undesired structural vibrations…

Fluid Dynamics · Physics 2021-09-21 Tiemo Pedergnana , Claire Bourquard , Abel Faure-Beaulieu , Nicolas Noiray

Relationships between inter-cluster synchronization phenomena and external noise are studied on the basis of noise level-free analysis. We consider a mean-field model of ensembles of coupled limit cycle oscillators with two natural…

Statistical Mechanics · Physics 2011-01-04 K. Okumura , A. Ichiki , M. Shiino
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