Analysis of a Grooved-Ring Reactor Concept for Nuclear Thermal Propulsion
- Paper number
IAC-08.C4.7.-C3.5.6
- Author
Ms. Mishaal ashemimry, Florida Institute of Technology, United States
- Coauthor
Dr. Daniel Kirk, Florida Institute of Technology, United States
- Year
2008
- Abstract
Author: Mishaal Nasir Ashemimry Research Assistant Florida Institute of Technology Address: 150 W. University Blvd, Melbourne, FL 32901 Phone: (305)613-1111 Email: mishaal@ashemimry.com Abstract title: Analysis of a Grooved-Ring Reactor Concept for Nuclear Thermal Propulsion Abstract Category: A Many of the nuclear reactor cores developed during the Rover/NERVA programs were plagued by thermal fatigue, hot hydrogen corrosion, and large pressure losses. Particle bed reactor concepts attempted to mitigate these effects, but their geometries proved difficult to cool and developed thermally unstable and highly localized hot spots, which would lead to melting of core material. This thesis presents a novel reactor design, specifically for space propulsion, called the grooved-ring reactor. The design attempts to retain the benefits of previous concepts while alleviating thermal cracking and reducing pressure losses. Thermo-fluid analytical modeling of the core demonstrates potential for significantly improved performance over prior concepts. The nuclear core is sized for a candidate rocket for a Mars mission having 333,617 N (75,000 lbf) of thrust and a specific impulse around 900 seconds. The core is composed of 61 hexagonal elements which are approximately 1 meter long. The initial design of the grooved-ring reactor contains 486 rings within each element, which have an outer diameter of 10.16 cm (4 in), an inner diameter of 5.08 cm (2 in), and a thickness of 2 mm (0.79 in). Each ring has 36 curved triangular cross-sectional channels through which the hydrogen coolant/propellant flows. After optimization of the geometry of the grooved-ring reactor, it was determined that the groove height varies radially and axially. Moreover, the thickness of each ring is determined by the exit groove height, for example, the thickness of the central ring must be larger than 2mm to ensure and exit height of 2.1 mm. Using a preliminary power distribution for a single hexagonal element the performance of the grooved-ring concept is analyzed. An idealized case, where the wall temperature is made constant through a tailored power profile is also investigated. Additionally, a parametric study of the grooved-ring reactor illustrates that thermal stresses on the core material can be reduced by geometric optimization. Co-Author: Daniel R. Kirk, PhD Assistant Professor Florida Institute of Technology Address: 150 W. University Blvd, Melbourne, FL 32901 Phone: (321)674-7622 Email: dkirk@fit.edu
- Abstract document
- Manuscript document
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