Rapid advances in available computer technology in the past ten years coupled with the ever increasing costs associated with gas turbine combustor development testing led to considerable interest in the development of sophisticated numerical methods for the design and analysis of turbine engine combustors. The development and refinement of these methods has been taking place at GE Aircraft Engines since 1980 as part of an ongoing research and development project. Efforts associated with this project have achieved considerable progress to date, including the development of 2D/axisymmetric and full 3D versions of an improved elliptic numerical model (CONCERT), suitable for application to combustor related flow problems. The application of CONCERT to typical combustor performance problems has demonstrated its capabilities to provide useful and accurate design information resulting in less dependence on component testing. This has resulted in engineering productivity improvement and reduced costs associated with combustor performance development.

Gas turbine engineering faces many challenges in the constant strive to increase not only the efficiency of engines but also the various stages of development and design. Development of combustors have primarily consisted of empirical or semi-empirical modelling combined with experimental investigations. Due to the associated costs and development time a need exists for an alternative method of development. Although experimental investigations can never be substituted completely, mathematical models incorporating numerical methods have shown to be an attractive alternative to conventional combustor design methods. The purpose of this study is twofold: firstly, to experimentally investigate the physical properties associated with a research combustor that is geometrically representative of practical combustors: and secondly, to use the experimental measurements for the validation of a computational fluids dynamic model that was developed to simulate the research combustor using a commercial code. The combustor was tested at atmospheric conditions and is representative of practical combustors that are characterized by a turbulent, three-dimensional flow field. The single can combustor is divided into a primary, secondary and dilution zone, incorporating film cooling air through stacked rings and an axial swirler centred around the fuel atomizer. Measurements at different air/fuel ratios captured the thermal field during operating conditions and consisted of inside gas, liner wall and exit gas temperatures. An investigation of the different combustion models available, led to the implementation of the presumed-PDF model of unpremixed turbulent reaction. The computational grid included the external and internal flow field with velocity boundary conditions prescribed at the various inlets. Two-phase flow was not accounted for with the assumption made that the liquid fuel is introduced into the combustion chamber in a gas phase. Experimental results showed that incomplete combustion occurs in the primary zone, thereby reducing the overall efficiency. Also evident from the results obtained are the incorrect flow splits at the various inlets. Evaluation of the numerical model showed that gas temperatures inside the combustor are overpredicted. However, the numerical model is capable of capturing the correct distributions of temperatures and trends obtained experimentally. This study is successful in capturing detail temperature measurements that will be used for validation purposes to assist the development of a numerical model that can accurately predict combustion properties.

Gas turbine combustor design represents an ambitious task in numerical and experimental analysis. A significant number of competing criteria must be optimised within specified constraints in order to satisfy legislative and performance requirements. Currently, preliminary combustor flow and heat transfer design procedures, which by necessity involve semi-empirical models, are often restricted in their range of application. The objective of this work is the development of a versatile design tool able to model all conceivable gas turbine combustor types. A network approach provides the foundation for a complete flow and heat transfer analysis to meet this goal. The network method divides the combustor into a number of independent interconnected sub-flows. A pressure-correction methodology solves the continuity equation and a pressure-drop/flow-rate relationship. A constrained equilibrium calculation, incorporating mixing and recirculation models, simulates the combustion process. The new procedures are validated against numerical and experimental data within three annular combustors and one reverse flow combustor. A full conjugate heat transfer model is developed to allow the calculation of liner wall temperature characteristics. The effects of conduction, convection and radiation are included in the model. Film cooling and liner heat pick-up effects are included in the convection calculation. Radiation represents the most difficult mode of heat transfer to simulate in the combustion environment. A discrete transfer radiation model is developed and validated for use within the network solver. The effects of soot concentration on radiation is evaluated with the introduction of radial properties profiles. The accuracy of the heat transfer models are evaluated with comparisons to experimental thermal paint temperature data on a reverse flow and annular combustors. The resulting network analysis code represents a powerful design tool for the combustion engineer incoporati.