Systems and methods for suppressing thermo-acoustic instabilities in a Combustor

Technology: Suppressing thermo-acoustic instabilities in a Combustor

Category: Aerospace & Defense Technologies

Industry: Aerospace

Application: Aero engine gas turbines

Market: The global market size was reached USD 3.3 billion in 2023 and is projected to expand at 9.2% CAGR from 2024 to 2032

Turbulent flows like gas turbine combustors can experience thermoacoustic instability due to large amplitude periodic oscillations.
This instability can cause extensive damage to combustor parts, leading to fatigue failure, loss of system performance, and mission failure.
Smart control strategies have been developed to mitigate this instability, including acoustic dampers, liners, staged fuel injection, and microjet injections.
Passive control involves modifying combustor geometry, altering fuel injection mechanisms, installing baffles, Helmholtz resonators, and applying acoustic liners.
Active control strategies supply energy to the thermoacoustic system through dynamic actuators, divided into active closed-loop and open-loop control.

Generating first and second signals for combustor’s turbulent velocity and acoustic pressure fluctuations.
Determining phase locked values for signal synchronization.
Measuring parameters for recurring turbulent velocity fluctuations at each combustor location.
Determining Hurst exponent values based on first signal.
Identifying critical region for phase locked values, recurring fluctuations, and Hurst exponent values.
Injecting micro-jets to suppress thermo-acoustic instabilities.

Detecting Combustion Instabilities:

Determining phase locked values across the combustor to indicate synchronization of turbulent velocity and acoustic pressure.
Using Hilbert transform to determine phase difference of first and second signals.
The phase locked value corresponds to a correlation between turbulent velocity and acoustic pressure.
Measures recurring fluctuations in turbulent velocity including recurrence rate, determinism, entropy, trapping time, and average diagonal length.
Measures a Euclidian distance between state points of the phase space trajectory at every combustor location.
Hurst exponent values indicate scaling behavior of the first signal corresponding to turbulent velocity.
Detects a critical region of the combustor at a region in the combustor.

Advancement:

Hurst exponent value is close to zero for periodic signals and greater than 0.5 for noisy and fractal signals.

Prof. Sujith RI

Department of Aerospace Engineering

TRL- 4

Experimentally validated in Lab

Technology Transfer