Session: 04-29 Hydrogen II

Submission Number: 178759

Design and Aerothermal Assessment of Two- and Three-Stage Sequential Combustors for Hydrogen and Multifuel Gas Turbines 

Achieving global net-zero emission targets requires the development of clean and adaptable combustion technologies compatible with hydrogen and hydrogen-based fuel blends. Among current research pathways, sequential and staged combustor architectures have demonstrated strong potential for NOₓ reduction through precise control of heat release and inter-stage mixing. This study presents a feasibility assessment of the preliminary aerothermal design of two- and three-stage hydrogen-fueled combustors, representative of high-pressure continuous-flow gas-turbine systems used in both power generation and propulsion applications.

This study presents an assessment of the aerothermal design of two- and three-stage hydrogen-fueled combustors, representative of high-pressure gas-turbine systems for both power generation and propulsion. The objective was to evaluate how different fuel-staging ratios  influence the aerothermal behavior of the combustor, including temperature fields, pressure losses, and predicted NOₓ trends under representative operating conditions. Numerical simulations were performed using ANSYS Fluent, focusing on the detailed flow structure, thermal distribution, and cooling-air management. These simulations were complemented by thermodynamic cycle analysis in Aspen Plus, enabling evaluation of the broader system-level effects of sequential combustion on Brayton-cycle performance, turbine inlet temperature, and overall thermal efficiency.

The approach involved assessing sequential operation under both pure hydrogen and multifuel conditions. For the two-stage configuration, pilot-stage fuel splits of 10%, 20%, and 30% were examined with hydrogen as the primary fuel, while in the multifuel mode, hydrogen was blended with Jet-A, ammonia, natural gas to evaluate flame stability and emission trends. The three-stage configuration extended this concept further, introducing hydrogen–ammonia blends, along with methane, natural gas, and Jet-A, distributed between stages in varying proportions (typically 10–20% per stage) to assess adaptability and performance under fuel-flexible operation.

The two-stage design with a 10% pilot split produced the most uniform temperature field and yielded approximately a 10% reduction in predicted thermal NOₓ compared with a single-stage baseline. The three-stage configuration exhibited smoother axial temperature gradients, improved outlet pattern factor, and no measurable penalties in pressure loss or overall thermal efficiency.

The results confirmed the potential of sequential multifuel hydrogen combustion as a pathway for low-NOₓ and fuel-flexible operation in hydrogen-ready gas turbines. Additionally, the integration of adaptive cooling technologies is proposed to enhance combustor performance under variable fuel compositions. These emerging approaches collectively contribute toward sustainable and decarbonized propulsion and power-generation systems aligned with global net-zero objectives.

Presenting Author: Yash Chougale University of Staffordshire

Presenting Author Biography: Yash Chougale is an Aeronautical Engineering graduate with a strong interest in sustainable propulsion and gas turbine technologies. He has hands-on experience in CFD-based combustor analysis, aerothermal optimization, and performance evaluation of hydrogen-fueled systems. His current work focuses on low-emission combustion and advanced cooling concepts aimed at improving efficiency and reducing environmental impact in future engines.

Authors:

Yash Chougale University of Staffordshire
Hamidreza Gohari Darabkhani University of Staffordshire