ABSTRACT
The use of probabilistic methods in gas turbine engine design is a rapidly growing field, with wide applications in various design disciplines such as performance, aero, heat transfer, and mechanical design. For example, probabilistics can be used to obtain a better understanding of engine performance and to define robust engine cycles that provide specified levels of performance in the presence of component/ hardware variation. Probabilistic models can also be used to support aircraft/engine integration studies to optimize customer-based parameters such as the direct cost of fleet operations. This chapter focuses on the use of probabilistics in structural design, in particular, the design of rotating parts within the engine. Figure 3.1 provides a cross section of a modern commercial turbofan engine. The focus of this discussion is on the rotating parts — the fan, compressor, and turbine — with particular attention paid to design issues involving damage tolerance and fatigue. Given the complexities of the overall problem, this chapter can only provide an overview of the probabilistic methods available. The discussion begins with a summary of traditional reliability engineering methods.
