Recommended Practices for Monitoring Gas Turbine Engine Life Consumption (Practiques Recommandees pour le Controle du Vieillisement des Turbomoteurs)
Abstract
The main reason for usage monitoring is to ensure that gas-turbine engine components do not fail in service. Early maintenance policies were based on a "hard-time" philosophy, measured in hours of use. More recently, technical advances have permitted a trend towards a condition-based philosophy. Life monitoring systems have evolved to automate measurement of the life used in modern engines. In many cases, the new assessment and monitoring methods have been applied to ageing fleets with great success. This document describes the design and operational factors that should be considered prior to the application of these techniques to an aged engine fleet. Turbine disks are the most safety critical parts, due to the amount of energy released should they fail. Moreover, future improvements in engine performance directly depend on increases in component stress levels. These demands for better performance must be met within the regulatory requirements for safety standards. This situation presents one of the most challenging areas of gas turbine design. Satisfying these conflicting demands carries a cost that reaches far beyond the development and purchase costs of a particular engine design. Although turbine disks are particularly expensive to make, over 90% of them are thrown away when less than 50% of their life has been consumed. Physical use, component life and safety have to be managed on a statistical basis because of variations in material properties.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2000
- Accession Number
- ADA380949
Entities
Organizations
- NATO Science and Technology Organization