Transient Performance Analysis of a Two Spool Turbofan for Lifing and Handling Purposes

The handling of a gas turbine and its life usage are closely related. As the handling capability required from an engine increases so does the life consumption. Faster transients and response require higher temperature levels, this reduces component lives. The phenomenon investigated here is thermal fatigue and the main focus is in the hot section of the engine, specifically the turbine blades.To make a quantitative assessment of the reduction of life due to the requirement of a faster transient response a simulation code of a two spool turbofan engine has been developed. It has a routine that estimates the High Pressure Turbine blade metal temperature. This temperature has been used to estimate the reduction of life loss when fast shaft accelerations are required.The main conclusion of this work is that, as expected, fast transients consume life faster. The present investigations suggest a quantitative level of thermal life reduction of approximately twenty five to thirty percent when comparing a fast acceleration of two to three seconds with a slower one of eight to ten seconds.Copyright © 1997 by ASME