Design and development of combustor for micro gas turbine engine

Wong, Chu Yan (2025). Design and development of combustor for micro gas turbine engine. University of Birmingham. Ph.D.

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Abstract

This thesis describes the early-stage design and development of a combustor for a turbogenerator with a radial configuration as a future range extender for electric vehicles. A novel curved-shape combustor is proposed, and a computational fluid dynamics (CFD) model was constructed to study the combustor performance.

The modelling strategy in this work was developed by studying iso-thermal flow followed by reacting flow simulations. To confirm the applicability of the strategy to modelling the proposed micro gas turbine combustor, it was applied to a swirling spray flame in a lab-scaled kerosene burner for which experimental data was available.

Flamelet generation manifold (FGM) with a prescribed joint probability density function (PDF) was employed for modelling the spray flame in designing and developing a micro gas turbine combustion chamber. The two-way coupling between droplets and the gaseous field was modelled by a Eulerian–Lagrangian approach. The enthalpy loss due to spray evaporation was considered in the FGM flamelet tabulation.

The work then continued by using design of experiment (DoE) to investigate the effect of the geometric and operational effects on the major chemical species and key operational parameters.

The optimisation of the combustor using the results of DoE and CFD models was presented and showed that the optimised combustor can potentially reduce the CO emissions by 88%, NOx by 31%, and soot by 83%. In addition, the optimised combustor showed that the combustor average outlet temperature met the requirements, and the pattern factor decreased by 41%, while the total pressure drop across the combustor increased by only 0.1%.

In summary, this thesis demonstrates the capability of the present modelling strategy to simulate a novel combustor with complex geometry as a design tool and DoE to identify the significant parameters and to determine the optimal parameter settings that give minimum pollutant emissions and maximum thermal performance.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):