Author : Jonathan F. Metscher
Publisher :
Page : 124 pages
File Size : 18,25 MB
Release : 2014
Category : Free piston engines
ISBN :
Using the Sage 1-D Stirling modeling software, a linear alternator model was developed using two separate methods and integrated with an existing ASC Stirling engine model. One used a simplified transducer method, while the other was developed from first principles. The combined models were tuned and validated against test data and then compared against each other. Both validated models are able to match test data within 7% or better.
Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
Page : 38 pages
File Size : 27,94 MB
Release : 2018-05-20
Category :
ISBN : 9781719370363
Free-piston Stirling power conversion has been considered a candidate for radioisotope power systems for space for more than a decade. Prior to the free-piston Stirling architecture, systems were designed with kinematic Stirling engines with rotary alternators to convert heat to electricity. These systems were proposed with lightly loaded linkages to achieve the necessary life. When the free-piston configuration was initially proposed, it was thought to be attractive due to the relatively high conversion efficiency, acceptable mass, and the potential for long life and high reliability. These features have consistently been recognized by teams that have studied technology options for radioisotope power systems. Since free-piston Stirling power conversion was first considered for space power applications, there have been major advances in three general areas of development: demonstration of life and reliability, the success achieved by Stirling cryocoolers in flight, and the overall developmental maturity of the technology for both flight and terrestrial applications. Based on these advances, free-piston Stirling convertors are currently being developed for a number of terrestrial applications. They commonly operate with the power, efficiency, life, and reliability as intended, and much of the development now centers on system integration. This paper will summarize the accomplishments of free-piston Stirling power conversion technology over the past decade, review the status, and discuss the challenges that remain. Schreiber, Jeffrey G. Glenn Research Center FREE-PISTON ENGINES; NUCLEAR ELECTRIC POWER GENERATION; COMPUTATIONAL FLUID DYNAMICS; POWER CONVERTERS; TECHNOLOGY UTILIZATION; RADIOISOTOPE HEAT SOURCES; MECHANICAL ENGINEERING; PISTON ENGINES; SYSTEMS INTEGRATION; RELIABILITY ANALYSIS; SOLAR CELLS; AC GENERATORS; LINKAGES; PANELS; CRYOGENIC COOLING; FAULT TOLERANCE; ORGANIC MATERIALS; LINEAR ALTERNATORS; MAGNETS; SPACECRAFT POWER SUPPLIES
Author :
Publisher :
Page : 492 pages
File Size : 18,83 MB
Release : 1994
Category : Aeronautics
ISBN :
Author : Jack G. Slaby
Publisher :
Page : 5 pages
File Size : 13,9 MB
Release : 1987
Category : Space vehicles
ISBN :
Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
Page : 142 pages
File Size : 20,16 MB
Release : 2018-07-17
Category :
ISBN : 9781723086304
As 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. Penswick, L. Barry and Beale, William T. and Wood, J. Gary Unspecified Center ENGINE DESIGN; HEAT TRANSFER; PISTON ENGINES; SPACE POWER REACTORS; STIRLING ENGINES; GAS BEARINGS; HEAT RESISTANT ALLOYS; PRESSURE VESSELS; REFRA...
Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
Page : 26 pages
File Size : 42,58 MB
Release : 2018-06-21
Category :
ISBN : 9781721639724
A dynamic model for a free-piston Stirling convertor is being developed at the NASA Glenn Research Center. The model is an end-to-end system model that includes the cycle thermodynamics, the dynamics, and electrical aspects of the system. The subsystems of interest are the heat source, the springs, the moving masses, the linear alternator, the controller, and the end-user load. The envisioned use of the model will be in evaluating how changes in a subsystem could affect the operation of the convertor. The model under development will speed the evaluation of improvements to a subsystem and aid in determining areas in which most significant improvements may be found. One of the first uses of the end-toend model will be in the development of controller architectures. Another related area is in evaluating changes to details in the linear alternator. Regan, Timothy F. and Gerber, Scott S. and Roth, Mary Ellen Glenn Research Center NASA/TM-2004-212941, E-14381
Author : Jeffrey G. Schreiber
Publisher :
Page : 18 pages
File Size : 46,64 MB
Release : 2000
Category :
ISBN :
Free-piston Stirling technology efforts in the past typically were intended to address power needs in the multi-kilowatt range. The Stirling power option was attractive primarily because of the high conversion efficiency and potential for long life. In recent years, several technology efforts have focused on the free-piston Stirling power d convertor for space power applications, however the more recent efforts are intended to provide power at levels far below one kilowatt. Through a variety of projects funded by both NASA and DOE, the free-piston Stirling convertor technology has successfully demonstrated high efficiency and long life. Other areas of concern, such as control of multi-convertor systems, and vibration reduction have also been addressed. Efforts are being initiated to address issues such as electro-magnetic interference (EMI), radiation tolerance of organic materials, and the ability to operate through launch loads and survive with integrity. The status of the technology in these areas will be briefly discussed in this paper.
Author :
Publisher :
Page : 20 pages
File Size : 50,15 MB
Release : 1994
Category :
ISBN :
An overview is presented of the NASA Lewis Research Center free-piston Stirling engine activities directed toward space power. This work is being carried out under NASAs̀ new Civil Space Technology Initiative (CSTI). The overall goal of CSTIs̀ High Capacity Power element is to develop the technology base needed to meet the long duration, high capacity power requirements for future NASA space missions. The Stirling cycle offers an attractive power conversion concept for space power needs. Discussed in this paper is the completion of the Space Power Demonstrator Engine (SPDE) testing - culminating in the generation of 25 kW of engine power from a dynamically-balanced opposed-piston Stirling engine at a temperature ratio of 2.0. Engine efficiency was approximately 22 percent. The SPDE recently has been divided into two separate single-cylinder engines, called Space Power Research Engines (SPRE), that now serve as test beds for the evaluation of key technology disciplines. These disciplines include hydrodynamic gas bearings, high-efficiency linear alternators, space qualified heat pipe heat exchangers, oscillating flow code validation, and engine loss understanding. The success of the SPDE at 650 K has resulted in a more ambitious Stirling endeavor - the design, fabrication, test and evaluation of a designed-for-space 25 kW per cylinder Stirling Space Engine (SSE). The SSE will operate at a hot metal temperature of 1050 K using superalloy materials. This design is a low temperature confirmation of the 1300 K design. It is the 1300 K free-piston Stirling power conversion system that is the ultimate goal; to be used in conjunction with the SP-100 reactor. The approach to this goal is in three temperature steps. However, this paper concentrates on the first two phases of this program - the 650 K SPDE and the 1050 K SSE.
Author : Graham Walker
Publisher : Springer Science & Business Media
Page : 282 pages
File Size : 26,29 MB
Release : 2012-12-06
Category : Technology & Engineering
ISBN : 3642825265
DEFINITION AND NOMENCLATURE A Stirling engine is a mechanical device which operates on a closed regenerative thermodynamic cycle with cyclic compression and expansion of the working fluid at different temperature levels. The flow of working fluid is controlled only by the internal volume changes, there are no valves and, overall, there is a net conversion of heat to work or vice-versa. This generalized definition embraces a large family of machines with different functions; characteristics and configurations. It includes both rotary and reciprocating systems utilizing mechanisms of varying complexity. It covers machines capable of operating as a prime mover or power system converting heat supplied at high tempera ture to output work and waste heat at a lower temperature. It also covers work-consuming machines used as refrigerating systems and heat pumps abstracting heat from a low temperature source and delivering this plus the heat equivalent of the work consumed to a higher tem perature. Finally it covers work-consuming devices used as pressure generators compressing a fluid from a low pressure to a higher pres sure. Very similar machines exist which operate on an open regen erative cycle where the flow of working fluid is controlled by valves. For convenience these may be called Ericsson engines but unfortunate ly the distinction is not widely established and regenerative machines of both types are frequently called 'Stirling engines'.
Author :
Publisher :
Page : 884 pages
File Size : 31,70 MB
Release : 1996
Category : Direct energy conversion
ISBN :
