Gas turbine critical component temperature predictions for fatigue life and integrity considerations

摘要

This paper addresses the issue of component temperature predictions for gas turbine engine critical parts. Existing civil air-engine airworthiness authority certification requirements and recent advances in thermomechanical modeling capability are reviewed. The concept of a whole-engine thermomechanical model is introduced, which enables the calculation of the transient boundary conditions in the secondary airflow systems surrounding critical parts, such as disks and shafts, and gives component temperature and displacement predictions. It is shown how these models can be used in the early stages of a new engine project for component design optimization, which can be developed throughout the 'life' of the engine to cover Certification and Life Management of the critical components. Reference is made to the application of CFD to the problems of establishing fluid flow distribution and heat transfer in internal cavities. This is illustrated with an example of the application of CFD modeling to a specific engine geometry, with comparisons to engine test data measurements. A recommendation for a revised means of compliance with certification authority requirements for critical part life and integrity considerations is made; it takes account of advances in methodology and the use of an existing validation data base.