Multi-disciplinary design optimization of a combustor

Abstract

A technique for design optimization of a combustor is presented. This technique entails the use of computational fluid dynamics (CFD) and mathematical optimization to minimize the combustor exit temperature profile. The empirical and semi-empirical correlations commonly used for optimizing combustor exit temperature profile do not guarantee optimum. As an experimental approach is time consuming and costly, use is made of numerical techniques. However, using CFD without mathematical optimization on a trial and error basis does not guarantee optimal solutions. A better approach, which is often viewed as too expensive, is a combination of the two approaches, thus incorporating the influence of the variables automatically. In this study the combustor exit temperature profile is optimized. The optimum (uniform) combustor exit temperature profile mainly depends on the geometric parameters. Combustor parameters have been used as optimization variables. The combustor investigated is an experimental liquid-fuelled atmospheric combustor with a turbulent diffusion flame. The CFD simulations use the Fluent code with a standard k-ε model. The optimization is carried out using the Dynamic-Q algorithm, which is specifically designed to handle constrained problems where the objective and constraint functions are expensive to evaluate. The optimization leads to a more uniform combustor exit temperature profile compared with the original.

Flame transfer function shaping for robust thermoacoustic systems: Application to a kinematic flame model

“…These methods do not require knowledge of the underlying physics, but perform a black-box type of optimization by iteratively changing parameters and assessing the improvement. Although some studies report on optimization of steady quantities in combustion, [7][8][9][10] optimization involving combustion dynamics poses specific challenges. Consequently, studies on such applications are rare.…”

Comparison of Response Surface Based Preliminary Design Methodologies for a Gas Turbine Combustor

“…Motsamai 1 , et al used CFD design runs with a Dynamic-Q optimization algorithm to improve the exit temperature profile of a combustor. Several studies [2][3][4][5] have used Reynolds Averaged Navier Stokes (RANS) based CFD simulations combined with the Design of Experiments (DOE) algorithms to improve combustor performance by varying geometric and operational design variables.…”