Papers by Richard Shaltens
For many years NASA has used the decay of Pu-238 (in the form of the General Purpose Heat Source ... more For many years NASA has used the decay of Pu-238 (in the form of the General Purpose Heat Source (GPHS)) as a heat source for Radioisotope Thermoelectric Generators (RTG), which have provided electrical power for many NASA missions. While RTG's have an impressive reliability record for the missions in which they have been used, their relatively low thermal to electric conversion efficiency (-5% efficiency) and the scarcity of Plutoinium-238 (Pu-238) has led NASA to consider other power conversion technologies. NASA is considering returning both robotic and human missions to the lunar surface and, because of the long lunar nights (14 earth days) isotope power systems are an attractive candidate to generate electrical power. NASA is currently developing the Advanced Stirling Radioisotope Generator (ASRG) as a candidate higher efficiency power system that produces greater than 160 watts with 2 GPHS modules at the beginning of life (BOL) (-30% efficiency). The ASRG uses the same Pu-238 GPHS modules, which are used in RTG, but by coupling them to a Stirling convertor provides a 4-fold reduction in the number of GPHS modules. This study considers the use of Americium 241 (Am-241) as a substitute for the Pu-238 in Stirling convertor based Radioisotope Power Systems (RPS) for power levels from 1 O's of watts to 5 kWe. The Am-241 is used as a replacement for the Pu-238 in GPHS modules. Depending on power level, different Stirling heat input and removal systems are modeled. It was found that substituting Am-241 GPHS modules into the ASRG reduces power output by about 1/5 while maintaining approximately the same system mass. In order to obtain the nominal 160 watts electrical output of the Pu-238 ASRG requires 10 Am-241 GPHS modules. Higher power systems require changing from conductive coupling heat input and removal from the Stirling convertor to either pumped loops or heat pipes. Liquid metal pumped loops are considered as the primary heat transportation on the hot end and water pumped loop/heat pipe radiator is considered for the heat rejection side for power levels above 1 kWe.
AGU Fall Meeting Abstracts, Dec 1, 2005
The Department of Energy is developing the Stirling Radioisotope Generator (SRG110) for NASAs Sci... more The Department of Energy is developing the Stirling Radioisotope Generator (SRG110) for NASAs Science Mission Directorate for potential surface and deep space missions. The SRG110 is one of two new radioisotope power systems (RPSs) currently being developed for NASA space missions, and is capable of operating in a range of planetary atmospheres and in deep space environments. It has a mass of approximately 27 kg and produces more than 125We(dc) at beginning of mission (BOM), with a design lifetime of fourteen years. Electrical power is produced by two (2) free-piston Stirlings convertor heated by two General Purpose Heat Source (GPHS) modules. The complete SRG110 system is approximately 38 cm x 36 cm and 76 cm long. The SRG110 generator is being designed in 3 stages: Engineering Model, Qualification Generator, and Flight Generator. Current plans call for the Engineering Model to be fabricated and tested by October 2006. Completion of testing of the Qualification Generator is scheduled for mid-2009. This development is being performed by Lockheed Martin, Valley Forge, PA and Infinia Corporation, Kennewick, WA under contract to the Department of Energy, Germantown, Md. Glenn Research Center, Cleveland, Ohio is providing independent testing and support for the technology transition for the SRG110 Program.
For many years, NASA has used the α decay of plutonium-238 (Pu-238) (in the form of the General P... more For many years, NASA has used the α decay of plutonium-238 (Pu-238) (in the form of the General Purpose Heat Source (GPHS)) as a heat source for Radioisotope Thermoelectric Generators (RTGs), which have provided electrical power for many NASA missions. While RTGs have an impressive reliability record for the missions in which they have been used, their relatively low thermal to electric conversion efficiency and the scarcity of plutonium-238 (Pu-238) has led NASA to consider other power conversion technologies. NASA is considering returning both robotic and human missions to the lunar surface and, because of the long lunar nights (14.75 Earth days), isotope power systems are an attractive candidate to generate electrical power. NASA is currently developing the Advanced Stirling Radioisotope Generator (ASRG) as a candidate higher efficiency power system that produces greater than 160 W with two GPHS modules at the beginning of life (BOL) (~32% efficiency). The ASRG uses the same Pu-238 GPHS modules, which are used in RTG, but by coupling them to a Stirling convertor provides a four-fold reduction in the number of GPHS modules. This study considers the use of americium-241 (Am-241) as a substitute for the Pu-238 in Stirlingconvertor-based Radioisotope Power Systems (RPS) for power levels from tens of W to 5 kWe. The Am-241 is used as a substitute for the Pu-238 in GPHS modules. Depending on power level, different Stirling heat input and removal systems are modeled. It was found that substituting Am-241 GPHS modules into the ASRG reduces power output by about one-fifth while maintaining approximately the same system mass. In order to obtain the nominal 160 W of electrical output of the Pu-238 ASRG requires 10 Am-241 GPHS modules. Higher power systems require changing from conductive coupling heat input and removal from the Stirling convertor to either pumped loops or heat pipes. Liquid metal pumped loops are considered as the primary heat transportation on the hot end and water pumped loop/heat pipe radiator is considered for the heat rejection side for power levels above 1 kWe. Nomenclature GPHS General Purpose Heat Source MLI multi-layer insulation RPS Radioisotope Power Systems RTG Radioisotope Thermoelectric Generator FeNdB iron neodymium boron SmCo samarium cobalt ASRG advanced Stirling radioisotope generator BOL Beginning-of-Life NASA/TM-2010-216352 2 EOL End-of-Life DOE Department of Energy Mar-M247 super alloy SOA State-of-the-Art LM Lockheed Martin Corp. 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER OF PAGES 33 19a. NAME OF RESPONSIBLE PERSON
3rd International Energy Conversion Engineering Conference, Jun 19, 2005
This report contains preliminary findings, subject to revision as analysis proceeds.
The broad objectives o f the Mod-1 program are defined, including the background information lead... more The broad objectives o f the Mod-1 program are defined, including the background information leading t o the inception of the program. A c t i v i t i e s on the Mod-1 program began i n 1974, and the turbine was dedicated i n July 1979. Rated power generation was accomplished i n February 1980. The Mod-1 wind turbine i s described i n t h i s report. I n addition t o the steel blade operated on the wind turbine, a composite blade was designed and manufactured. During the early phase o f the manufacturing cycle a Mod-1A conf iguration was designed that i d e n t i f i e d concepts such as p a r t i a l span control, a soft tower, and upwir~d teetered rotors that have been incorporated i n second-and third-generation industry designs. The Hod-1 e l e c t r i c a l system perf omed as designed, with voltage f 1 icker characteristics within acceptable u t i 1 i t y 1 i m i ts. Power output versus wind speed has equaled or exceeded design predictions. The wind turbine control system was operated successfully at the s i t e and remotely frm the u t i l i t y dispatcher's o f f i c e i n Lenoir, N.C. Ouring wind turbine operations, television interference was experienced by the local residents. As a consequence, operations were restrictea. A1 though not implemented, two potential solutions were identified. I n addition t o television inter-fereXe, a few local residents complained about objectionable sound, part i c u l a r l y the *thumpu as the blade passed behind the tower. To eliminate the residents' objections, the sound generation level was reduced by 10 dB by reducing the rotor speed from 35 rpm t o 23 rpm. During January 1981, bolts i n the drive t r a i n fractured. A solution has been ioentified but not implemented as yet. During the past 2 years the public reaction toward the Mod-1 Wino Turbine program has been overwhe Imingly f avornble. This includes the vast majority of Boone residents.
NASA's Glenn Research Center (GRC) has been developing advanced energy conversion technologies fo... more NASA's Glenn Research Center (GRC) has been developing advanced energy conversion technologies for use with both Radioisotope Power Systems (RPS) and Fissions Surface Power Systems (FSPS) for many decades[1, 2, 3]. Under NASA's Science Mission Directorate, Planetary Science Theme, Technology Program, GRC is developing the next generation of Advanced Stirling Convertors (ASC) for use in the DOE/Lockheed Martin Advanced Stirling Radioisotope Generator (ASRG) [4, 5.] The next generation power conversion technologies require high efficiency and high specific power (We/kg) to meet future mission requirements using less of the Department of Energy (DOE's) Plutonium fueled General Purpose Heat Source (GPHS) Modules and reducing the system mass. Important goals include long-life (> 14 years) reliability, and scalability so that these systems can be considered for a variety of future applications and missions including outerplanetary missions and continual operation on the surface of Mars. This paper provides an update of the history and status of the development of the Advanced Stirling Convertor (ASC) being developed for GRC by Sunpower Inc., Athens, OH.
IEEE Transactions on Power Apparatus and Systems, May 1, 1984
Nucleation and Atmospheric Aerosols, 1993
Closed Brayton cycle power conversion systems are readily adaptable to any heat source contemplat... more Closed Brayton cycle power conversion systems are readily adaptable to any heat source contemplated for space application. The inert gas working fluid can be used directly in gas-cooled reactors and coupled to a variety of heat sources (reactor, isotope or solar) by a heat exchanger. This point is demonstrated by the incorporation in the NASA 2 kWe Solar Dynamic (SD)
IEEE Transactions on Power Apparatus and Systems, Jun 1, 1983
This paper presents a bibliography of selected references pertain¬ ing to electrical distribution... more This paper presents a bibliography of selected references pertain¬ ing to electrical distribution system planning. An extensive, but not necessarily complete, search has been made for the identification of papers and reports published in the open literature which describe the distribution planning methods and techniques. Emphasis is placed on references which illustrate prac¬ tical as well as theoretical applications of distribution system plan¬ ning techniques. The listing of the titles is subdivided into three sections, depending upon the general substance of each article. However, a title may be listed in more than one section if the paper covers material in various sections. The entries \n each section are listed in alphabetical order. The last name of the first order author determines the alphabetical position. Many of the articles are available in abstract form in Science Ab¬ stracts, Section B, of the Engineering Index, and digesting or index¬ ing periodicals, as well as in the original magazines listed. Only the more readily available foreign publications are included.
AIP Conference Proceedings, 1999
This report documents the operating experience with two aluminum blades used on the DOE/NASA Mod-... more This report documents the operating experience with two aluminum blades used on the DOE/NASA Mod-OA 200-kilowatt wind turbine located at Clayton, New Mexico. Each Mod-OA aluminum blade is 59.9 feet long and weighs 2,360 pounds. The aluminum blades originally used on the Mod-0, 100-kilowatt wind turbine test bed, near Sandusky, Ohio, are described. The Mod-0 aluminum blaoes were developed and tested before the Mod-OA aluminum blades were designed. Early Mod-0 blaae tests showed a need for blades having higher load carrying capability. As a result, the Mod-OA blades were developed with the Mod-0 blades serving as prototypes. The aluminum Mod-OA blade design requirements, the selected design, fabrication procedures, and the blade analyses are discusseo. A detailed chronology is presented on the operating experience of the Mod-OA aluminum blades used at Clayton, New Mexico. Blade structural damage was experienced. Inspection and damage assessment were required. Structural modifications that were incorporated to the blacies successfully extended the useful operating life of the blades. The aluminum blades completed the planned 2 years of operation of the Clayton wind turbine. The blades were removed from service in August 1980 to allow testing of advanced technology wood composite blades.
NTlS price codes1 Printed copy: A02 Microfiche copy: A01 lCodes are used for pricing all publicat... more NTlS price codes1 Printed copy: A02 Microfiche copy: A01 lCodes are used for pricing all publications. The code is determined by the number of pages in the publication. Information pertaining to the pricing codes can be found in the current issues of the following publications, which are generally available in most libraries: Energy Research Abstracts (ERA); Government Reports Announcements and Index
This document was prepared under the sponsorship of the National Government assumes any liability... more This document was prepared under the sponsorship of the National Government assumes any liability resulting from the use of the Aeronautics and Space Administration Nether the United States information contained in this document, or warrants that such use Government nor any person acting on behalf of the United States will be free from privately owned rights.
NASA Tech Briefs, Apr 1, 1993
... Lanny G Thieme, Diane M Swec (1992). ... Effect of Solar Collector Design Parameters on the O... more ... Lanny G Thieme, Diane M Swec (1992). ... Effect of Solar Collector Design Parameters on the Operation of Solar Stirling Power System. Narendra Singh, BM Gibbs, SC Kaushik in International Journal of Energy Research (1997). Save reference to library · Related research 1 ...
Testing has been conducted on a 2 kW, Solar Dynamic system in a large thermal/vacuum facility wit... more Testing has been conducted on a 2 kW, Solar Dynamic system in a large thermal/vacuum facility with a simulated Sun at the NASA Lewis Research Center. The solar dynamic system includes a Brayton conversion unit integrated with a heat receiver which includes thermal energy storage for continuous power generation throughout a typical low-Earth orbit sun/eclipse cycle. System testing to date has accumulated over 500 hrs of power generation, ranging from 400 watts to over 2.0 kW,, including nearly 300 simulated orbits (249 producing power), 23 ambient starts and 3 hot restarts in a relevant environment. This paper will review the test program, including both operational and performance data. Data will be shown for an orbital startup and both transient and steady state orbital operation. System performance sensitivities are also discussed. The system testing is providing the experience and confidence for using solar dynamic technologies for future space power applications.
Government-funded studies for adapting the Stirling engine to an automotive application started i... more Government-funded studies for adapting the Stirling engine to an automotive application started in 1971. The initial studies were to reduce exhaust emissions and were later broadened to include fuel economy and alternate fuels. With the passage of the Automotive Propulsion Research and Development Act of 1978, the studies matured into the current Automotive Stirling Engine (ASE) Program. After eight years of development effort, the accomplishments of the ASE Program are reviewed to assess the outlook for program success at its scheduled completion in September 1987. One important goal of the ASE program is the transfer of Stirling engine technology to the USA. The technology transfer to the ASE Program team members has been accomplished. To expand the transfer in the USA, various activities have been initiated to make available the developed automotive Stirling engine technology to other US industries, including nonautomotive.
Under NASA's Civil Space Technology Initiative (CSTI), the NASA Lewis Research Center is ... more Under NASA's Civil Space Technology Initiative (CSTI), the NASA Lewis Research Center is developing the technology needed for free-piston Stirling engines as a candidate power source for space systems in the late 1990's and into the next century. Space power requirements include high efficiency, very long life, high reliability, and low vibration. Furthermore, system weight and operating temperature are important.
STIN, Mar 1, 1995
The Solar Dynamic (SD) Ground Test Demonstration (GTD) program demonstrates the availability of S... more The Solar Dynamic (SD) Ground Test Demonstration (GTD) program demonstrates the availability of SD technologies in a simulated space environment at the NASA Lewis Research Center (LeRe) vacuum facility. Data from the SD GTD program will be provided to the joint U.S. and Russian team which is currently designing a 2 kW SD flight demonstration power system. This SD technology has the potential as a future power source for the International Space Station. This paper reviews the goals and status of the SD GTD program. A description of the SD GTD system includes key design features of the system, subsystems and components. 19. SECURITY CLASSIFICATION 20. LIMIT A TION OF ABSTRACT
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Papers by Richard Shaltens