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Free-piston Stirling engine conceptual design and technologies for space power, phase 1As part of the SP-100 program, a phase 1 effort to design a free-piston Stirling engine (FPSE) for a space dynamic power conversion system was completed. SP-100 is a combined DOD/DOE/NASA program to develop nuclear power for space. This work was completed in the initial phases of the SP-100 program prior to the power conversion concept selection for the Ground Engineering System (GES). Stirling engine technology development as a growth option for SP-100 is continuing after this phase 1 effort. Following a review of various engine concepts, a single-cylinder engine with a linear alternator was selected for the remainder of the study. The relationships of specific mass and efficiency versus temperature ratio were determined for a power output of 25 kWe. This parametric study was done for a temperature ratio range of 1.5 to 2.0 and for hot-end temperatures of 875 K and 1075 K. A conceptual design of a 1080 K FPSE with a linear alternator producing 25 kWe output was completed. This was a single-cylinder engine designed for a 62,000 hour life and a temperature ratio of 2.0. The heat transport systems were pumped liquid-metal loops on both the hot and cold ends. These specifications were selected to match the SP-100 power system designs that were being evaluated at that time. The hot end of the engine used both refractory and superalloy materials; the hot-end pressure vessel featured an insulated design that allowed use of the superalloy material. The design was supported by the hardware demonstration of two of the component concepts - the hydrodynamic gas bearing for the displacer and the dynamic balance system. The hydrodynamic gas bearing was demonstrated on a test rig. The dynamic balance system was tested on the 1 kW RE-1000 engine at NASA Lewis.
Document ID
Document Type
Contractor Report (CR)
Penswick, L. Barry
(SunPower, Inc. Athens, OH, United States)
Beale, William T.
(SunPower, Inc. Athens, OH, United States)
Wood, J. Gary
(Wood, J. Gary, Albany OH , United States)
Date Acquired
September 6, 2013
Publication Date
January 1, 1990
Subject Category
Spacecraft Propulsion And Power
Report/Patent Number
NAS 1.26:182168
Accession Number
Funding Number(s)
PROJECT: RTOP 586-01-11
Distribution Limits
Work of the US Gov. Public Use Permitted.
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