Three-Dimensional Analyses of Skutterudite-Based Segmented Unicouples with Metallic Coating
- Chemical and Nuclear Engineering Dept., University of New Mexico, Albuquerque, NM, 87131 (United States)
This paper presents the results of a 3-D performance analysis of Skutterudite-Based Segmented Unicouple (SKU) with nine {mu}m thick Molybdenum (Mo) coatings on n- and p-legs near the hot junction. The analysis performed at hot and cold junction temperatures of 973 K and 300 K investigated the effect of the coating on lateral distributions of the electric current, voltage, and temperatures in the legs and the conversion efficiency and electric power generated by the unicouple. The p- and n-legs are 20 mm long and have hot and cold segments of CeFe3.5Co0.5Sb12 and Bi0.4Sb1.6Te3, and of CoSb3 and Bi2Te2.95Se0.05, respectively. The cross-section area of the p-leg is 11 mm2. The cross sectional area of the n-leg and the lengths of the Mo coatings and of various segments of the legs are determined for maximum conversion efficiency using a 1-D optimization model. The 3-D analysis performed with ANSYS finite element commercial software used the dimension determined by the 1-D model. Results show that the electric currents near the outer surface of the Mo coatings flow in the opposite direction to those in the n- and p-legs. In very thin parts of legs near the interface with the coatings, electric currents flow in the same direction as in the coatings, but decrease rapidly with inward distance from the interface, eventually becoming zero, then flowing in the same direction as the electric current in the legs. Such current circulation increases joules losses in the coated parts of the hot segments of the legs, decreasing the conversion efficiency. The increased heat flow from the hot shoe through the metallic coatings contributes to decreasing the conversion efficiency, but increasing the electric power generated by SKU.
- OSTI ID:
- 20798008
- Journal Information:
- AIP Conference Proceedings, Vol. 813, Issue 1; Conference: 10. conference on thermophysics applications in microgravity; 23. symposium on space nuclear power and propulsion; 4. conference on human/robotic technology and the national vision for space exploration; 4. symposium on space colonization; 3. symposium on new frontiers and future concepts, Albuquerque, NM (United States), 12-16 Feb 2006; Other Information: DOI: 10.1063/1.2169238; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
A CODES
COATINGS
DISTRIBUTION
EFFICIENCY
ELECTRIC CURRENTS
ELECTRIC POTENTIAL
ELECTRIC POWER
ENERGY CONVERSION
FINITE ELEMENT METHOD
HEAT FLUX
INTERFACES
MOLYBDENUM
MOLYBDENUM ALLOYS
OPTIMIZATION
PERFORMANCE
RADIOISOTOPES
SURFACES
THERMOELECTRIC GENERATORS
NESDPS Office of Nuclear Energy Space and Defense Power Systems