Four TDC's are now being tested at Glenn. Acceptance testing has been completed for all convertors, and in general, performance agreed well with that achieved by STC prior to the delivery of the convertors. Performance mapping has also been completed on two of the convertors over a range of hot-end temperatures (450 to 650 °C), cold-end temperatures (80 to 120 °C), and piston amplitudes (5.2 to 6.2 mm). These test data are available online. The TDC's can be tested in either a horizontal orientation with dual-opposed convertors or in a vertical orientation with a single convertor. Synchronized dual-opposed pairs are used for dynamically balanced operation that results in very low levels of vibration. The Stirling Research Laboratory also supports launch environment testing of the TDC's in Glenn's Structural Dynamics Laboratory and electromagnetic interference and electromagnetic compatibility characterization and reduction efforts. In addition, the TDC's will be used for long-term endurance testing, and preparations are underway for unattended operation.

Stirling Technology Demonstration Convertors being tested at Glenn in both
dual-opposed and single convertor modes of operation.
Long description
A competitive procurement by DOE for the Stirling Radioisotope Generator system integration contractor is nearing completion. Following announcement of the selected contractor, Glenn will continue to provide critical support for the overall DOE project as the work moves into system development. Other key efforts underway at Glenn are a life assessment of the TDC heater head, including creep testing of the Inconel 718 hot-end material and accelerated life testing of prototypical heater heads, long-term aging characterization of NdFeB permanent magnets used in the linear alternator, finite element analyses of the linear alternator in particular to determine the demagnetization margin of the permanent magnets, evaluation of the TDC organic materials used in the piston bearing coatings and linear alternator insulations and adhesives, support for DOE reliability assessments, and development of a multidimensional Stirling computational fluid dynamics performance code.

Full-stroke performance map for the Stirling Technology
Demonstration Convertor.
Long description
Find out more about this research from Glenn's Thermo-Mechanical Systems Branch.
Glenn contacts: Richard Shaltens, 216-433-6138,
Richard.K.Shaltens@grc.nasa.gov;
Jeff Schreiber, 216-433-6144, Jeffrey.G.Schreiber@grc.nasa.gov; and Lanny Thieme,
216-433-6119, Lanny.G.Thieme@grc.nasa.gov
Author: Lanny G. Thieme
Headquarters program office: OSS
Programs/Projects: Stirling Radioisotope Generator, Mars rover, Outer Planets
Special recognition: Space Technology and Applications
International Forum (STAIF) 2000 Outstanding Paper Award for paper
entitled "Technology Development for a Stirling Radioisotope Power System"
Last updated: June 2002
Responsible NASA Official:
Gynelle.C.Steele@nasa.gov
216-433-8258
Point of contact for NASA Glenn's Research & Technology reports:
Cynthia.L.Dreibelbis@nasa.gov
216-433-2912
SGT, Inc.
Web page curator:
Nancy.L.Obryan@nasa.gov
216-433-5793
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