R. Murner, P. Wawrzonek, Test Devices, Hudson, MA
Higher gas turbine flow path temperatures have steadily increased the rim-to-bore gradients on both the rear stages of high pressure compressors and high pressure turbines. This has increased the likelihood of TMF related lifing issues with the disk live rims and with creep and stress rupture failures of disk blade attachment lugs. Lifing models enter a realm of high uncertainty when significant plasticity is present as a percentage of total cyclic strain and the result is more frequent and expensive inspection of service components in order to prevent potentially catastrophic liberation of parts. Other turbine hardware such as blade retention plates, rivets, dampers and even blade attachments cannot escape the effects of increased temperatures that border the creep regimes of the latest turbine superalloys.
For decades TMF testing of rotating structures has not been practical since the localized heating and cooling methods required were not available. Recent advances in focused heating methods have now made TMF a viable test option for material and engine development programs. Quartz lamps and lasers offer exceptional focused thermal flux combined with capabilities that lend themselves to digital programming and control. The prior issues of not being able to rapidly cycle heating and cooling on narrow annuli of disks no longer exist.
The objective of this briefing is to present the results of an aft stage compressor TMF test that was recently performed by Test Devices Incorporated. The test component was a fully bladed, retired F100 10th stage compressor disk. The briefing highlights the unique design features of the test rig, presents the test results and offers insight into the potential of the test method to investigate the issues related to hot section rotors.
Summary: Higher gas turbine flow path temperatures have steadily increased the rim-to-bore gradients on both the rear stages of high pressure compressors and high pressure turbines. This has increased the likelihood of TMF related lifing issues with the disk live rims and with creep and stress rupture failures of disk blade attachment lugs. Lifing models enter a realm of high uncertainty when significant plasticity is present as a percentage of total cyclic strain and the result is more frequent and expensive inspection of service components in order to prevent potentially catastrophic liberation of parts. Other turbine hardware such as blade retention plates, rivets, dampers and even blade attachments cannot escape the effects of increased temperatures that border the creep regimes of the latest turbine superalloys.
For decades TMF testing of rotating structures has not been practical since the localized heating and cooling methods required were not available. Recent advances in focused heating methods have now made TMF a viable test option for material and engine development programs. Quartz lamps and lasers offer exceptional focused thermal flux combined with capabilities that lend themselves to digital programming and control. The prior issues of not being able to rapidly cycle heating and cooling on narrow annuli of disks no longer exist.
The objective of this briefing is to present the results of an aft stage compressor TMF test that was recently performed by Test Devices Incorporated. The test component was a fully bladed, retired F100 10th stage compressor disk. The briefing highlights the unique design features of the test rig, presents the test results and offers insight into the potential of the test method to investigate the issues related to hot section rotors.
