Nonlinearity, noise, and statistics in natural convective flows

Conference · Wed Jan 01 04:00:00 EST 1992 · Transactions of the American Nuclear Society; (United States)

OSTI ID:7056055

Dorning, J ^[1]

---

1. Univ. of Virginia, Charlottesville (United States)

Many of the inherent safety features of advanced reactor designs rely heavily on natural thermal convection in the form of closed or open thermosyphon loops, such as reactor vessel auxiliary air-cooling systems in liquid-metal reactors (LMRs), and closed or open pools, such as the sodium pool in which an LMR core is immersed. Hence, it is clear that a rather complete understanding of natural thermal convection in open and closed loops and pools is extremely important to the safety of these new nuclear technologies. In this paper, the author reviews some of the now well-known facts concerning the fundamentals of natural convection that have been discovered and understood for {approximately} 10 yr, and then the author reports some new results that demonstrate the kinds of significant effects that noise can have on the transient and long-time behaviors of convective systems and on the statistic of their final states whether they be steady, periodic, or aperiodic. The noise introduced into the analyses summarized here can be interpreted either as real noise that arises in the engineering system and truly affects its actual time evolution, or as computer noise that could arise during large-scale computer simulations. Analyses of simple model convection systems in the presence of noise suggest possible nonlinear phenomena that could arise in more complex real systems or subsystems such as in a thermally stratified layer of an LMR pool.

• OSTI ID: 7056055
• Report Number(s): CONF-920606--
• Conference Information: Journal Name: Transactions of the American Nuclear Society; (United States) Journal Volume: 65
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210500 -- Power Reactors
Breeding
22 GENERAL STUDIES OF NUCLEAR REACTORS
220900* -- Nuclear Reactor Technology-- Reactor Safety
ALKALI METALS
BOUNDARY CONDITIONS
CONTAINERS
CONVECTION
CONVERGENCE
COOLING SYSTEMS
DESIGN
ELEMENTS
ENERGY TRANSFER
HEAT TRANSFER
ITERATIVE METHODS
KINETICS
LIQUID METAL COOLED REACTORS
MASS TRANSFER
MATHEMATICAL MODELS
METALS
NATURAL CONVECTION
NONLINEAR PROBLEMS
PHYSICS
PRIMARY COOLANT CIRCUITS
REACTOR COMPONENTS
REACTOR COOLING SYSTEMS
REACTOR CORES
REACTOR KINETICS
REACTOR NOISE
REACTOR PHYSICS
REACTOR SAFETY
REACTOR VESSELS
REACTORS
SAFETY
SODIUM
THERMOSYPHON EFFECT