Session: Student Poster Competition

Submission Number: 187002

Prediction of Combustion Instability in Hydrogen–methane Gas Turbine Combustors Using Flamelet-Based Framework and One-Dimensional Network Model 

In response to increasingly stringent emission regulations and global decarbonization efforts, hydrogen co-firing in gas turbines has attracted significant attention as a practical pathway for reducing carbon emissions in the power generation sector. However, due to the high reactivity of hydrogen compared to methane, hydrogen blending can significantly increase susceptibility to combustion instabilities, posing critical challenges to stable gas turbine operation. In this study, a multi-scale framework is developed and validated to predict combustion instability characteristics in an industrial-scale single-nozzle hydrogen–methane co-firing combustor. Experimental results indicate that increasing operating pressure and hydrogen blending ratio lead to amplified dynamic pressure oscillations and shortened flame lengths, resulting in enhanced combustion instability behavior.

To reproduce these experimental trends while maintaining computational efficiency, a coupled approach integrating a flamelet-based framework and a one-dimensional network model is proposed. First, steady-state three-dimensional RANS simulations are performed and validated against experimental data to accurately capture baseline flame structure. Subsequently, a RANS-based Flamelet Generated Manifold (FGM) framework is applied across a range of operating conditions to efficiently resolve complex flame characteristics, from which characteristic time delay (τ), a key parameter governing dynamic flame response, is systematically extracted.

Extracted time-delay parameters are then incorporated into a one-dimensional network model representing a combustor system consisting of a plenum, nozzle, and a combustion chamber. System stability evaluation and sensitivity analyses are conducted using the n–τ flame model. Results demonstrate that the proposed multi-scale framework quantitatively reproduces experimentally observed trends in combustion instability and variations in stability margin with respect to changes in operating pressure and hydrogen blending ratio. These findings indicate that the proposed approach provides a practical and reliable tool that simultaneously preserves physical fidelity and computational efficiency, and can be effectively utilized for combustion instability prediction and stability-oriented design of hydrogen co-firing gas turbine combustors.

Presenting Author: Jaewoo Jang Gangneung-Wonju National University

Presenting Author Biography: Jaewoo Jang is a Ph.D. candidate in the Department of Mechanical Engineering at Gangneung–Wonju National University, South Korea. His research focuses on combustion instability analysis using one-dimensional thermoacoustic modeling and CFD-based reacting flow simulations.

Authors:

Daesik Kim Gangneung-Wonjui National University
Jaewoo Jang Gangneung-Wonju National University
Min Kuk Kim Korea Institute of Machinery and Materials
Jeongjae Hwang Korea Institute of Machinery and Materials
Won June Lee Korea Institute of Machinery and Materials