Optimal mixing of multiple reacting jets in a gas turbine combustor

Abstract

Paper presented at the 6th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 30 June - 2 July, 2008.

This paper addresses the design optimisation methodology used to optimise a gas turbine combustor exit temperature profile. The methodology uses computational fluid dynamics and mathematical optimisation to optimise the combustor exit temperature profile. The studies from which the results were derived, investigated geometric variations of a complex three-dimensional flow field in a gas turbine combustor. The variation of geometric parameters impacts on mixing effectiveness, of which the combustor exit temperature profile is a function. The combustor in this study is an experimental liquid-fuelled atmospheric combustor with a turbulent diffusion flame. The computational fluid dynamics simulations use the Fluent code with a standard k-ε model. The optimisation is carried out with the Dynamic-Q algorithm, which is specifically designed to handle constrained problems where the objective and constraint functions are expensive to evaluate. All the optimisation cases investigated led to an improved combustor exit temperature profile as compared to the original one.