ULUK, Heval Serhat
(2025)
Numerical analysis of alternative fuels in trapped vortex combustor.
PhD thesis, University of Nottingham.
Abstract
The production of greenhouse gases resulting from high energy demands has increased significantly over the past year, highlighting the urgent need to develop advanced combustion systems capable of utilizing alternative fuels. The increasing demand for more efficient and environmentally friendly propulsion systems is particularly critical in the aviation sector, where strict weight and performance constraints are required. The Trapped Vortex Combustor (TVC) is a promising design known for its enhanced combustion efficiency, low pressure drops, and reduced NOx emissions. In this approach, fuel is directly injected into a cavity where air-fuel mixing occurs and creates a pilot flame. The direct injection of fuel combined with aerodynamic mixing makes the TVC a viable option for utilizing alternative fuels. In this thesis, TVC was tested for propane, ammonia, hydrogen, and ammonia/hydrogen mixtures for non-reacting and reacting simulation, especially ammonia haven’t been tested in TVC. It was aimed at improving the performance of TVC, by inclination of the air injectors on various transverse and lateral directions.
Non-reacting simulations showed that the 30° transverse angled air injectors, and 30° transverse and 15° lateral angled air injectors increase the mixing efficiency and lower the total pressure drop. These air injector arrangements with default configuration were simulated under reactive conditions to evaluate combustion characteristics. It was found that the 30° transversely angled air injectors showed high mixing efficiency, overall combustion efficiency, low static pressure drop, and high combustion efficiency inside the cavity, with low NOx emissions. Moreover, comparing ammonia and hydrogen combustion performance with propane indicates that the transverse and lateral angle implementation are more impactful in their performance. After the 30° transverse angled air injectors were chosen as the best for alternative fuel, mixture of ammonia and hydrogen was used in TVC. The results showed that 50% hydrogen and 50% ammonia mixture is the optimum mixture because it has very high combustion efficiency inside the cavity, good mixing efficiency, and pattern factor, with low peak temperature compared to other mixtures while having low NOx emissions. The TVC’s performance was also tested under realistic operating conditions. It was found that TVC can perform well for atmospheric, idle and low power operating conditions, and all the values showed favourable and acceptable levels, meeting the combustion characteristics criteria.
| Item Type: |
Thesis (University of Nottingham only)
(PhD)
|
| Supervisors: |
Dakka, Sam
Singh, Kuldeep |
| Keywords: |
trapped vortex combustor, propulsion, computational fluid dynamics, alternative fuels, gas turbines |
| Subjects: |
T Technology > TL Motor vehicles. Aeronautics. Astronautics |
| Faculties/Schools: |
UK Campuses > Faculty of Engineering
UK Campuses > Faculty of Engineering > Department of Mechanical, Materials and Manufacturing Engineering |
| Item ID: |
81765 |
| Depositing User: |
ULUK, HEVAL
|
| Date Deposited: |
31 Dec 2025 04:40 |
| Last Modified: |
31 Dec 2025 04:40 |
| URI: |
https://eprints.nottingham.ac.uk/id/eprint/81765 |
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