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Joseph R. VanderVeer

Bio: Joseph R. VanderVeer is an academic researcher. The author has contributed to research in topics: Stirling engine & Radioisotope thermoelectric generator. The author has an hindex of 1, co-authored 5 publications receiving 3 citations.

Papers
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Proceedings ArticleDOI
01 Mar 2019
TL;DR: Free piston Stirling convertor based generators present a significant advantage over traditional radioisotope power systems (radioisotopes thermoelectric generators) which is conversion efficiency, but a significant portion of the analysis focuses on reliability of the configurations.
Abstract: Free piston Stirling convertor based generators present a significant advantage over traditional radioisotope power systems (radioisotope thermoelectric generators), which is conversion efficiency. Several configurations are considered ranging from 50 We to 500 We. Current dynamic systems have yet to prove themselves with respect to reliability. Therefore, a significant portion of the analysis focuses on reliability of the configurations. As dynamic convertor reliability has yet to be determined generator reliability studies are relative to convertor reliability. Reliability studies include the system controller, individual convertor controllers, and convertor redundancy. In addition to reliability: power, thermal efficiency, conversion efficiency, and weight are considered. Investigated configurations show system level efficiencies as high as 24% are possible.

3 citations

Proceedings ArticleDOI
01 Mar 2020
TL;DR: System integration of a Stirling convertor into a generator requires trade studies and in depth system analysis of a variety of subsystems, including several off-nominal conditions and effects of failed convertors upon the system.
Abstract: Free piston Stirling convertors offer increased efficiency over radioisotope thermoelectric generators at the potential expense of increased risk to reliability and robustness. Steps in reducing that risk are system studies that integrate Stirling convertors into a generator. System integration of a Stirling convertor into a generator requires trade studies and in depth system analysis of a variety of subsystems. Subsystems focused upon here are the GPHS to convertor heating mechanism, convertor and system level heat rejection system, and the overall physical/mechanical configuration. An overview of several system design options and rationale for the down selection of the final configuration are presented. Included in the analysis is several off-nominal conditions and effects of failed convertors upon the system. Initial simulations showed a system efficiency of 21% and specific power of 3.9 W/kg, updated higher fidelity models and details indicate a system efficiency of 23% and a specific power of 3.0 W/kg for the reference condition are possible.

2 citations

Proceedings ArticleDOI
01 Mar 2017
TL;DR: The Centralized Math Engine or CME, a substantial need for the development of a modern SINDA replacement was needed for the enhanced Multi-Mission Radioisotope Thermoelectric Generator (eMMRTG), and a few implementation examples are discussed in detail.
Abstract: Space applications often utilize the NASA developed Systems Improved Numerical Differencing Analyzer (SINDA) for thermal systems analysis. SINDA is primarily meant to be a computer programming language designed to assist in the solution of finite difference problems. However, due to a substantial desire to maintain backwards compatibility, SINDAs development environment and performance have lagged behind modern capabilities and techniques. Some such techniques are object oriented programming, integrated debugger, and parallel processing. In the development of the enhanced Multi-Mission Radioisotope Thermoelectric Generator (eMMRTG), a substantial need for the development of a modern SINDA replacement was needed. This need prompted the creation of the Centralized Math Engine or CME. The theory, design, development and a few implementation examples are discussed in detail. The thermal models require substantially less time to develop, requiring approximately 80 vs 280 man-hours. A specific thermal model showed a speed up of 18.75x versus the SINDA equivalent due to the use of more sophisticated linear solvers.
Proceedings ArticleDOI
06 Mar 2021
TL;DR: In this article, the authors proposed a custom modeling tool for radioisotope thermoelectric generator (RTG) performance prediction, and compared the performance with the commercial solutions.
Abstract: Custom high-performance-computing software is expensive and time consuming to develop and verify; therefore, expending the resources to develop such software needs to be rationalized. Predicting radioisotope thermoelectric generator (RTG) performance is such a case where the software development effort can be justified. Some of the demands of such a modeling tool are time and temperature dependent material properties, anisotropic materials, quasi-steady state analysis, thousands of components, multi-physics (thermal conduction, thermal radiation, electrical conduction, thermoelectric effect, sublimation, etc.), and variable dimensions. Each of the above will slow down the computation of a single simulation, combining that slow down with the need to perform multi-parameter non-linear optimization, Monte Carlo analysis, and parametric studies; thousands to millions of simulations are often required. Current commercial general-purpose modeling tools meet the RTG modeling demands, but run times are impractical and/or require expensive computational resources (cost prohibitive or scheduling prohibitive). This leads to the effort to design a custom modeling tool for RTG's. The financial costs, personnel costs, and performance are compared for a variety of modeling solutions including other custom options and commercial software. Benefits of configuration management options, verification options, validation options, and long-term support are discussed. Lastly, the versatility of the custom model versus the commercial solutions are compared.

Cited by
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Proceedings ArticleDOI
01 Mar 2020
TL;DR: System integration of a Stirling convertor into a generator requires trade studies and in depth system analysis of a variety of subsystems, including several off-nominal conditions and effects of failed convertors upon the system.
Abstract: Free piston Stirling convertors offer increased efficiency over radioisotope thermoelectric generators at the potential expense of increased risk to reliability and robustness. Steps in reducing that risk are system studies that integrate Stirling convertors into a generator. System integration of a Stirling convertor into a generator requires trade studies and in depth system analysis of a variety of subsystems. Subsystems focused upon here are the GPHS to convertor heating mechanism, convertor and system level heat rejection system, and the overall physical/mechanical configuration. An overview of several system design options and rationale for the down selection of the final configuration are presented. Included in the analysis is several off-nominal conditions and effects of failed convertors upon the system. Initial simulations showed a system efficiency of 21% and specific power of 3.9 W/kg, updated higher fidelity models and details indicate a system efficiency of 23% and a specific power of 3.0 W/kg for the reference condition are possible.

2 citations

Journal ArticleDOI
TL;DR: In this article , the authors present a survey of the evolution of technical programs and examine the multidisciplinary skills required to accelerate the transition of nuclear batteries from laboratory prototypes to fully functional systems.
Abstract: The batteries fuelled by radio‐isotopes have represented a significant technological solution for planetary science and exploration missions since the beginning of the space era. Now emerging researches and new concepts are making the nuclear batteries attractive also for relevant terrestrial applications. The present survey aims to summarize the evolution of technical programmes and to examine the multidisciplinary skills required to accelerate the transition of nuclear batteries from laboratory prototypes to fully functional systems.

1 citations

Proceedings ArticleDOI
09 Aug 2021

1 citations

Journal ArticleDOI
TL;DR: In this paper , a self-developed numerical model of the whole system, coupled with a third-order model of free-piston Stirling engine (FPSE) was proposed for the first time, and a nuclear-powered Stirling system comprising eight 1 kW FPSEs was designed.