Integrated Propulsion and Power Modeling for Bimodal Nuclear Thermal Rockets

Four nuclear thermal rocket (NTR) models have been created in the Numerical Propulsion System Simulation (NPSS) framework. The models are divided into two categories. One set is based upon the ZrC-graphite composite fuel element and tie tube-style reactor developed during the Nuclear Engine for Rocket Vehicle Application (NERVA) project in the late 1960s and early 1970s. The other reactor set is based upon a W-UO2 ceramicmetallic (CERMET) fuel element. Within each category, a small and a large thrust engine are modeled. The small engine models utilize RL-10 turbomachinery performance maps and have a thrust of approximately 33.4 kN (7,500 lbf ). The large engine models utilize scaled RL-60 turbomachinery performance maps and have a thrust of approximately 111.2 kN (25,000 lbf ). Power deposition profiles for each reactor were obtained from a detailed Monte Carlo N-Particle (MCNP5) model of the reactor cores. Performance factors such as thermodynamic state points, thrust, specific impulse, reactor power level, and maximum fuel temperature are analyzed for each engine design.

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“…The theory behind the reactor and tie tube thermodynamics and fluid mechanics is summarized elsewhere. 5,6…”

Section: B Numerical Propulsion System Simulation (Npss) Frameworkmentioning

confidence: 99%

Nuclear Thermal Rocket Simulation in NPSS

Belair

Sarmiento

Lavelle

2013

49th AIAA/ASME/SAE/ASEE Joint Propulsion Conference

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“…The design considered here uses tungsten cermet fuel elements, containing uranium oxide or nitride in a tungsten or tungstenrhenium matrix. Clough examines a bimodal cermet NTR design with specific impulse potentially up to 933 s, and states a theoretical I sp of 975 s with chamber temperature of only 2560 K [19]. An engine designed for only brief use could run at higher temperature and I sp .…”

Section: Ntr Capabilitiesmentioning

confidence: 99%

“…The TRITON design expected a ratio above 8 using LOX augmentation [22], and the Timberwind program intended a ratio of 30 using a pebble bed reactor [23]. Because the interceptor is low-thrust (∼60 kN, comparable to NASA's Small Nuclear Rocket Engine [19]) adopting a more conservative ratio of 6 : 1 appears reasonable.…”

Section: Ntr Capabilitiesmentioning

confidence: 99%

Near-Earth Object Interception Using Nuclear Thermal Rocket Propulsion

Ball

Granier

et al. 2010

Proceedings of the Institution of Mechanical Engineers, Part G:

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Planetary defense has drawn wide study: despite the low probability of a large-scale impact, its consequences would be disastrous. The study presented here evaluates available protection strategies to identify bottlenecks limiting the scale of near-Earth object that could be deflected, using cutting-edge and near-future technologies. It discusses the use of a nuclear thermal rocket (NTR) as a propulsion device for delivery of thermonuclear payloads to deflect or destroy a long-period comet on a collision course with Earth. A ‘worst plausible scenario’ for the available warning time (10 months) and comet approach trajectory are determined, and empirical data are used to make an estimate of the payload necessary to deflect such a comet. Optimizing the tradeoff between early interception and large deflection payload establishes the ideal trajectory for an interception mission to follow. The study also examines the potential for multiple rocket launch dates. Comparison of propulsion technologies for this mission shows that NTR outperforms other options substantially. The discussion concludes with an estimate of the comet size (5km) that could be deflected using NTR propulsion, given current launch capabilities.

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