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Vapor turbine for space power
available for cases in which the rejected heat can only be lost b y radiation. For a given efficiency a n d Seebeck coefficient for materials h a v i n g the same efficiency it is shown t h a t the particular c o m b i n a t i o n of p a r a m e t e r s in these materials viz low electrical r e s i s t i v i t y and high t h e r m a l c o n d u c t i v i t y is the most desirable.
Kevane, Clement J., "Report on the Measurement of Thermal Diffusivity Using a Solar Furnace." Office of Naval Research Contract No. NR-032-419, June 1958. In order to develop a m e t h o d for m e a s u r e m e n t of t h e r m a l diffusivity of materials, the p r o p a g a t i o n of t e m p e r a t u r e waves set up b y periodic modulation of the heat flux in a solar furnace was studied at moderate t e m p e r a t u r e s . T h e experimental results were compared with a n analysis of one-dimensional heat flow u n d e r periodic excitation to determine t h e r m a l diffusivity. Because of small t e m p e r a t u r e oscillation amplitudes and r a t h e r large t e m p e r a t u r e fluctuations at the focal spot, work was limited to t e m p e r a t u r e s less t h a n 1000 C. The results are only in rough order of m a g n i t u d e agreement with known t h e r m a l diffusivities because of the t e m p e r a t u r e fluctuation noise a n d u n d e t e r m i n e d systematic errors.
Vickery, R. C., Muir, H. M., and Kleber, E. V., "Thermoelectric Properties of some Rare Earth Systems." Presented at ARS Space Power Systems Conference, Santa Monica, Calif., Sept. 27-30, 1960. 4 p. Illus. (1275-60). Compositions of gadolinium with o t h e r metals a n d metalloids have been examined for value as high t e m p e r a t u r e t h e r m oelectric materials. I n systems containing b i s m u t h , a n t i m o n y , silicon, boron, phosphorus, iron, nickel, cobalt and manganese, Seebeck emf's and resistivities are generally low (20-30 u v / C and 200-400 u-cm respectively). The gadolimium-selenimn s y s t e m presents however, intermetallic compounds with Seebeck o u t p u t s up to 600 u v / C a n d resistivities ranging from 0.2 to 1000 X 10-3-cm. Specific considerations are made of the p o t e n t i a l of this system.
VlII--Thermionic
Oman, Henry and Street, George, Jr., "Experimental Solar Thermionic Converter for Space Use." AIEE Pacific General Meeting, San Diego, Calif., August 8-12, 1960. Conference Paper, May 10, 1960. 8 p. Illus. (60-1040).
VI--Vapor, Hot Air, and Fluid Heat Engines
Bullock, Robert 0., "Vapor Turbine for Space Power." Presented at ARS Space Power Systems Conference, Santa Monica, Calif., Sept. 27-30, 1960. 20 p. Illus. (1327-60)
1. A high-pressure cesium-vapor type thermionic c o n v e r t e r h e a t e d by sunshine c o n c e n t r a t e d by a lightweight mirror appears to be a promising power source for space vehicles. 2. A procedure for designing solar-thermionic space-vehicle power sources has been developed. 3. Tests of a 15 w a t t solar h e a t e d thermionic c o n v e r t e r should establish valid design criteria for these converters.
Vapor t u r b i n e s for space power will require the use of unfamiliar fluids in unfamiliar conditions. In order to achieve long life, reliability, a n d efficiency, a t t e n t i o n must be given to problems t h a t previously were either n o n e x i s t e n t or could be economically ignored. Several p r o m i n e n t problems are raised; the b a c k g r o u n d i n f o r m a t i o n a b o u t t h e m is reviewed, a n d the research and development required to solve t h e m is outlined.
I X - - P h o t o c h e m i c a l Processes : Biological, Botanical and Inorganic
Hardwick, R., "Kinetic Studies of the Thionine-Iron System II," Dept. of Chemistry, Univ. of California, Los Angeles, Calif., 5 p. Illus.
Parker, M. D. and Smith, C. L., "Stirling Engine Development for Space Power." Presented at ARS Space Power Systems Conference, Santa Monica, Calif., Sept. 27-30, 1960. 34 p. Illus. (1315-60)
T h e observed i n h i b i t o r y effect of ferric ions on the bleaching of aqueous thionine-ferrous ion solutions has been formerly a t t r i b u t e d to direct quenching of excited thionine. The results of the present experiments, reinforced by recent d a t a of other authors, are used in an i n t e r p r e t a t i o n of the reaction mechanism which assigns a chemical, not quenching, rote to ferric ions.
The basic Stirling cycle is reviewed with respect to its a d v a n t a g e s and limitations for space power applications. An engine design for space power is discussed with p a r t i c u l a r emphasis on problems associated with the space e n v i r o n m e n t . Conditions for exact balance of dynamic forces are examined. Design a n d development approach to the l u b r i c a t i o n a n d sealing problems in a zero gravity e n v i r o n m e n t for long periods of u n a t t e n d e d operation is outlined. Finally, a Stirling cycle engine, designed a n d c o n s t r u c t e d b y the Allison Division of General Motors Corporation, is discussed.
X--Photoelectric: Piezoelectric
Photovoltaic,
Photogalvanic,
Dale, B., and Rudenberg, H. G., "Photovoltaic Conversion-High Efficiency Silicon Solar Cells." Transitron Electronic Corporation, Reprinted from 14th Annual Proceedings, Power Sources Conference, May 17-19, 1960. 4 p. Illus.
VII--Solar Furnaces
Hiester, Nevin K. and De La Rue, R. E., "The Image Furnace as a Research Tool." Reprinted from ARS Journal, Oct. 1960, 928-938 p. Illus.
The i m p r o v e m e n t s made in high efficiency silicon solar cells u n d e r a research s t u d y have been described. T h e y have raised the over-all conversion efficiency of the units from 10% to 15%, b y careful design of the cell structure. The work has raised the o u t p u t voltage of the cell, s u b s t a n t i a l l y lowered the series resistance, a n d has provided various surfaces with differing optical characteristics. A new t e t r a h e d r a l surface structure, as well as clear silicon surfaces a n d a d j u s t a b l e optical coatings have been shown. The i m p r o v e d ceils are capable of use with light c o n c e n t r a t o r s to increase the o u t p u t per cell a n d lower costs b y factors of 5 to 10 times. T h u s a
T h e purpose of this p a p e r is to provide a guide to t h e literat u r e covering some of the i m p o r t a n t theoretical and practical aspects of image furnaces and t h e i r operation. I n addition, some of the research areas where these devices h a v e been used will be briefly described in the hope t h a t it m a y trigger ideas for o t h e r ways in which t h e y can be used to solve research problems.
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Kevane, Clement J., "Report on the Measurement of Thermal Diffusivity Using a Solar Furnace." Office of Naval Research Contract No. NR-032-419, June 1958. In order to develop a m e t h o d for m e a s u r e m e n t of t h e r m a l diffusivity of materials, the p r o p a g a t i o n of t e m p e r a t u r e waves set up b y periodic modulation of the heat flux in a solar furnace was studied at moderate t e m p e r a t u r e s . T h e experimental results were compared with a n analysis of one-dimensional heat flow u n d e r periodic excitation to determine t h e r m a l diffusivity. Because of small t e m p e r a t u r e oscillation amplitudes and r a t h e r large t e m p e r a t u r e fluctuations at the focal spot, work was limited to t e m p e r a t u r e s less t h a n 1000 C. The results are only in rough order of m a g n i t u d e agreement with known t h e r m a l diffusivities because of the t e m p e r a t u r e fluctuation noise a n d u n d e t e r m i n e d systematic errors.
Vickery, R. C., Muir, H. M., and Kleber, E. V., "Thermoelectric Properties of some Rare Earth Systems." Presented at ARS Space Power Systems Conference, Santa Monica, Calif., Sept. 27-30, 1960. 4 p. Illus. (1275-60). Compositions of gadolinium with o t h e r metals a n d metalloids have been examined for value as high t e m p e r a t u r e t h e r m oelectric materials. I n systems containing b i s m u t h , a n t i m o n y , silicon, boron, phosphorus, iron, nickel, cobalt and manganese, Seebeck emf's and resistivities are generally low (20-30 u v / C and 200-400 u-cm respectively). The gadolimium-selenimn s y s t e m presents however, intermetallic compounds with Seebeck o u t p u t s up to 600 u v / C a n d resistivities ranging from 0.2 to 1000 X 10-3-cm. Specific considerations are made of the p o t e n t i a l of this system.
VlII--Thermionic
Oman, Henry and Street, George, Jr., "Experimental Solar Thermionic Converter for Space Use." AIEE Pacific General Meeting, San Diego, Calif., August 8-12, 1960. Conference Paper, May 10, 1960. 8 p. Illus. (60-1040).
VI--Vapor, Hot Air, and Fluid Heat Engines
Bullock, Robert 0., "Vapor Turbine for Space Power." Presented at ARS Space Power Systems Conference, Santa Monica, Calif., Sept. 27-30, 1960. 20 p. Illus. (1327-60)
1. A high-pressure cesium-vapor type thermionic c o n v e r t e r h e a t e d by sunshine c o n c e n t r a t e d by a lightweight mirror appears to be a promising power source for space vehicles. 2. A procedure for designing solar-thermionic space-vehicle power sources has been developed. 3. Tests of a 15 w a t t solar h e a t e d thermionic c o n v e r t e r should establish valid design criteria for these converters.
Vapor t u r b i n e s for space power will require the use of unfamiliar fluids in unfamiliar conditions. In order to achieve long life, reliability, a n d efficiency, a t t e n t i o n must be given to problems t h a t previously were either n o n e x i s t e n t or could be economically ignored. Several p r o m i n e n t problems are raised; the b a c k g r o u n d i n f o r m a t i o n a b o u t t h e m is reviewed, a n d the research and development required to solve t h e m is outlined.
I X - - P h o t o c h e m i c a l Processes : Biological, Botanical and Inorganic
Hardwick, R., "Kinetic Studies of the Thionine-Iron System II," Dept. of Chemistry, Univ. of California, Los Angeles, Calif., 5 p. Illus.
Parker, M. D. and Smith, C. L., "Stirling Engine Development for Space Power." Presented at ARS Space Power Systems Conference, Santa Monica, Calif., Sept. 27-30, 1960. 34 p. Illus. (1315-60)
T h e observed i n h i b i t o r y effect of ferric ions on the bleaching of aqueous thionine-ferrous ion solutions has been formerly a t t r i b u t e d to direct quenching of excited thionine. The results of the present experiments, reinforced by recent d a t a of other authors, are used in an i n t e r p r e t a t i o n of the reaction mechanism which assigns a chemical, not quenching, rote to ferric ions.
The basic Stirling cycle is reviewed with respect to its a d v a n t a g e s and limitations for space power applications. An engine design for space power is discussed with p a r t i c u l a r emphasis on problems associated with the space e n v i r o n m e n t . Conditions for exact balance of dynamic forces are examined. Design a n d development approach to the l u b r i c a t i o n a n d sealing problems in a zero gravity e n v i r o n m e n t for long periods of u n a t t e n d e d operation is outlined. Finally, a Stirling cycle engine, designed a n d c o n s t r u c t e d b y the Allison Division of General Motors Corporation, is discussed.
X--Photoelectric: Piezoelectric
Photovoltaic,
Photogalvanic,
Dale, B., and Rudenberg, H. G., "Photovoltaic Conversion-High Efficiency Silicon Solar Cells." Transitron Electronic Corporation, Reprinted from 14th Annual Proceedings, Power Sources Conference, May 17-19, 1960. 4 p. Illus.
VII--Solar Furnaces
Hiester, Nevin K. and De La Rue, R. E., "The Image Furnace as a Research Tool." Reprinted from ARS Journal, Oct. 1960, 928-938 p. Illus.
The i m p r o v e m e n t s made in high efficiency silicon solar cells u n d e r a research s t u d y have been described. T h e y have raised the over-all conversion efficiency of the units from 10% to 15%, b y careful design of the cell structure. The work has raised the o u t p u t voltage of the cell, s u b s t a n t i a l l y lowered the series resistance, a n d has provided various surfaces with differing optical characteristics. A new t e t r a h e d r a l surface structure, as well as clear silicon surfaces a n d a d j u s t a b l e optical coatings have been shown. The i m p r o v e d ceils are capable of use with light c o n c e n t r a t o r s to increase the o u t p u t per cell a n d lower costs b y factors of 5 to 10 times. T h u s a
T h e purpose of this p a p e r is to provide a guide to t h e literat u r e covering some of the i m p o r t a n t theoretical and practical aspects of image furnaces and t h e i r operation. I n addition, some of the research areas where these devices h a v e been used will be briefly described in the hope t h a t it m a y trigger ideas for o t h e r ways in which t h e y can be used to solve research problems.
144