SBIR-STTR Award

Test Devices proposes a program to develop and demonstrate a capability that imposes a radial temperature distribution as well as the centrifugal load on turbine engine disks in a spin test environment. This capability will simulate operating strain histories, i.e. thermal-mechanical fatigue (TMF), the results of which will permit more realistic service life predictions. The first phase involves demonstrating the feasibility of TMF in a spin rig by applying a constant temperature gradient across the test article. Phase 2 involves a technological step up with the inclusion of a cooled arbor and the acquisition and implementation of a quartz oven for high heat flux for accurate control of a real-world variable temperature distribution. The use of such a facility will provide a more accurate simulation of rotor operation to establish reliable service life and maintenance schedules for gas turbine components. The capability will directly contribute to the Durability initiatives of the VAATE program. Additionally, the capability would support the industry desire for more accurate physical testing as a prelude to eventual virtual testing. TDI has a demonstrated history of developing advanced spin pit technology and is thus well qualified to conduct this program.

Benefits:
The capability would support the industry desire for more accurate physical testing to not only verify and validate existing models, analyses and understandings of rotor life, but also provide a step towards eventual virtual testing. The capability will enable rotor lives to be extended safely and confidently, thus supporting the many related initativves within the ERLE program, the AIM program and VAATE. Commercial airline operators are particularly keen to see this capability developed because of the huge cost saving implications. Rotor manufacturers would also benefit from the outcome of this program by being able to sell a more durable and longer lasting (and therefore higher priced) product at the outset.

Keywords:
Thermal Mechanical Fatigue (TMF), temperature gradient, spin test, engine rotor life extension, gas turbine engine, thermal stress, centrifugal stress, Durability

The proposed effort will create the technology and systems necessary to create thermal gradients in jet engine components in a vacuum spin pit. The gradients created will create a strain state in the component under test which much more closely match the conditions in these components in engine service. All testing in the past has been conducted isothermally, and the results obtained have not been sufficently reliable for life prediction, since the test does not include the important effects of thermal gradients on the disk strain distribution and therefore on disk fatigue life. This project will produce the tools necessary to create, control, and manage thermal gradients in disks as they are being spun at high speed in a vacuum, concentrating on developing the systems and processes necessary to supply heat at the hotter region and remove heat at the cooler regions.

Keywords:
Lcf, Fatigue, Spin Pit, Turbomachinery, Disk, Tmf,