Overview of Turbine Design

This chapter reviews the aerodynamic design of turbines and the ways in which turbine design can be affected by nonaerodynamic considerations. Turbine configurations are discussed, along with typical gas turbine design goals and challenges. The work does not present a detailed description of how to design a turbine airfoil and analyze its performance; the reader is encouraged to review the references for such details. The primary focus of this treatise is rather to give an overall description of the design process and, more importantly, the considerations that produce a good design. A good turbine design is one that meets customer requirements of performance, durability, and cost of ownership with the least design and development time. The performance and durability depend on the designer’s ability to optimize the design using the best available tools. Minimizing costs will depend on the fidelity of the design process that can rapidly generate three-dimensional airfoil configurations and analyses that can investigate and incorporate performanceenhancing design features with minimal testing and design validation. The ultimate goal is to develop a design process of such high fidelity that any design feature can be incorporated flawlessly, eliminating the need for concept-rig and engine testing. To this end, two key advances in turbine design have been developed to maximize turbine performance: minimize cost of design and development and minimize time-to-market. The first of these is the implementation of a process for technology development that is focused on producing high-fidelity, physics-based tools capable of producing paradigm-shift geometry and predicting turbine performance without the need to test concept variants, once a predictive capability has been demonstrated. The second is automated, computer-based optimization