Final work : The Impact of Turbine Cooling and Sealing Flow Reduction on Disk Mechanical Integrity and Life

Abstract

New Cooling Technologies have been designed to increase the efficiency of future aircraft engines. The effects of cooling mass flow reduction and temperature variation on Lifing and Integrity of the disc of stage one of the high pressure turbine (HPT1) are investigated. In particular, the effects of the following new cooling technologies are analyzed: the Dual Wall Casted Blade (DW), the Cooled Cooling Air(CCA) and the Rotating Internal Heat Exchanger(RIHX). First results are no lifing and integrity effects on the DW technology and general positive effects introduced by CCA and RIHX. In particular, a reduction of cooling temperature at the drive arm of the disc, mainly introduced by the CCA, as well as an increase of temperature at the bore of the disc, introduced by the RIHX, improve the disc life. Moreover, the CCA introduces the best improvement in integrity between the analyzed cooling technologies. Consequently, a new cooling technology (NC), which introduces an optimization of integrity and lifing of both drive arm and bore of the disc, is proposed by the author of the thesis. In particular, the temperature reduction at the drive arm of 90K and the temperature increase at the bore of 90K introduced by the NC, reduce the thermal gradient within the rim and bore of the HPT1 disc and reduce the thermal stresses within the disc producing a positive effect on lifing and integrity.