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Development of a Phasor Diagram Creator to Visualize the Piston and Displacer Forces in an Advanced Stirling ConvertorThe steady-state, nearly sinusoidal behavior of the components in a free-piston Stirling engine allows for visualization of the forces in the system using phasor diagrams. Based on Newton's second law, F = ma, any phasor diagrams modeling a given component in a system should close if all of the acting forces have been considered. Since the Advanced Stirling Radioisotope Generator (ASRG), currently being developed for future NASA deep space missions, is made up of such nearly sinusoidally oscillating components, its phasor diagrams would also be expected to close. A graphical user interface (GUI) has been written in MATLAB (MathWorks), which takes user input data, passes it to Sage (Gedeon Associates), a one-dimensional thermodynamic modeling program used to model the Stirling convertor, runs Sage, and then automatically plots the phasor diagrams. Using this software tool, the effect of varying different Sage inputs on the phasor diagrams was determined. The parameters varied were piston amplitude, hot-end temperature, cold-end temperature, operating frequency, and displacer spring constant. These phasor diagrams offer useful insight into convertor operation and performance.
Document ID
20150021372
Acquisition Source
Glenn Research Center
Document Type
Technical Memorandum (TM)
Authors
Saha, Dipanjan
(Connecticut Univ. Storrs, CT, United States)
Lewandowski, Edward J.
(NASA Glenn Research Center Cleveland, OH, United States)
Date Acquired
November 17, 2015
Publication Date
December 1, 2013
Subject Category
Fluid Mechanics And Thermodynamics
Engineering (General)
Report/Patent Number
NASA/TM-2013-216549
GRC-E-DAA-TN7329-2
E-18725
NETS-2013-6760
Meeting Information
Meeting: Nuclear and Emerging Technologies for Space (NETS - 2013)
Location: Albuquerque, NM
Country: United States
Start Date: February 25, 2013
End Date: February 28, 2013
Sponsors: Aerojet-General Corp., American Nuclear Society
Funding Number(s)
WBS: WBS 138494.05.02.04.03
Distribution Limits
Public
Copyright
Public Use Permitted.
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