Impacts of low-pressure (LP) compressor’s deterioration upon an aero-engine’s high-pressure (HP) turbine blade’s life consumption

Abstract

Some in-service deterioration in any mechanical device, such as an aero-engine, is inevitable. As a result of experiencing a deterioration of efficiency and/or mass flow, an aero-engine will automatically adjust to a different set of operating characteristics; thereby frequently resulting in changes of rpm and/or turbine entry temperature in order to provide the same thrust. Rises in the turbine entry-temperatures and the high-pressure turbine’s rotational speed result in greater rates of creep and fatigue damage being incurred by the hot-end components and thereby higher engine’s life cycle costs. Possessing a better knowledge of the effects of engine deterioration upon the aircraft’s performance, as well as fuel and life usages, helps the users to take wiser management decisions and hence achieve improved engine utilisation. For a military aircraft, using a computer performance simulation, the consequences of low-pressure (LP) compressor’s deterioration upon an aero-engine high-pressure (HP) turbine blade’s life-consumption have been predicted.

Impacts of low-pressure (LP) compressor’s deterioration of a turbofan engine upon fuel-usage of a military aircraft

“…For the same TET level, the NT available from the engines and HPSS decrease with increasing LPC's deterioration. However, both of these engine parameters increase with increasing TETs (17) . Flight speed also has a significant effect on the required engine's NT, which decreases with increasing flight speed at low Ms because momentum drag predominates.…”

“…However, greater benefits will be achieved if the present analysis is considered as an integral part of a more comprehensive analysis including life usage, mission operational effectiveness, as well as life cycle costs aspects. The investigation regarding impacts of low-pressure (LP) compressor's deterioration upon an aero-engine's high-pressure (HP) turbine blade's life consumption has been already presented (17) . The detailed investigation regarding impacts of LPC's deterioration upon mission effectiveness as well as life cycle costs aspects is underway.…”

Impacts of low-pressure (LP) compressors’ fouling of a turbofan upon operational-effectiveness of a military aircraft

“…However, greater benefits will be achieved if the present analysis is considered as an integral part of a more comprehensive analysis including engine's life-usage, fuel-usage, as well as life-cycle costs aspects. The investigations regarding impacts of low-pressure (LP) compressor's deterioration upon an aero-engine's high-pressure (HP) turbine-blade's life, consumption, as well as overall fuel-usage of a military aircraft have been presented separately [24,25]. The detailed investigation regarding impacts of LPC's fouling upon an engine's optimal utilization and life-cycle costs aspects is underway.…”

Implications of day temperature variation for an aero-engine's HP turbine-blade's creep life-consumption

“…A slight difference in percentage values of safe life in terms of flight cycles and that in terms of hours is because of the dependency of flight Mach number/flight velocity on ID and thereby difference in time taken to complete the mission at different IDs as well as consideration of safe number of flight cycles in whole numbers toward lower side instead of exact values in decimal points. The adverse affect at higher IDs becomes even more severe for engines with fouled compressors [7,8]. For example for engines with 10% low pressure compressors' fouling, the blades' CrpD at ID 35 K is 10 times higher as compared with clean engines (i.e.…”

“…Significant adverse effects of in-service deterioration of an aero-engine have been already established by earlier investigations [7][8][9]. As a result of a comprehensive literature review, it was realized that besides deterioration of an aero-engine, the condition of fuel as well as of the incoming air stream is also expected to have significant effects on the aero-engine's over-E-mail address: naeem1947@hotmail.com.…”