Diffusive limits for particle transport in stochastic mixtures

Journal Article · Wed Apr 01 00:00:00 EST 1992 · Journal of Mathematical Physics (New York); (United States)

DOI:https://doi.org/10.1063/1.529725· OSTI ID:7278160

Sammartino, M; Malvagi, F; Pomraning, G C ^[1]

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1. School of Engineering and Applied Science, University of California, Los Angeles, Los Angeles, California 90024-1597 (United States)

Under the assumption of weak spatial and temporal gradients as well as weak absorption and sources, it is well known that the classic kinetic equation describing linear particle transport has a diffusion equation as an asymptotic limit. Considered here is such particle transport in a stochastic Markovian mixture of two immiscible fluids. It is shown that a variety of asymptotic diffusive limits exist under the scaling indicated above, depending upon the additional scaling introduced for the Markov transition lengths. These lengths are indicative of the mean chord lengths of the fluid packets in the stochastic mixture, and it is thus found that the details of the diffusive limits are strongly dependent upon the presumed sizes of the fluid packets. Asymptotically consistent initial and boundary conditions are also derived for each diffusion description obtained.

• DOE Contract Number: FG03-89ER14016
• OSTI ID: 7278160
• Journal Information: Journal of Mathematical Physics (New York); (United States), Vol. 33:4; ISSN 0022-2488
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
DIFFUSION
KINETIC EQUATIONS
MIXTURES
ASYMPTOTIC SOLUTIONS
BOUNDARY CONDITIONS
DISTRIBUTION FUNCTIONS
MARKOV PROCESS
NEUTRON TRANSPORT THEORY
SCALING
STOCHASTIC PROCESSES
TRANSPORT THEORY
DISPERSIONS
EQUATIONS
FUNCTIONS
661300* - Other Aspects of Physical Science- (1992-)
663610 - Neutron Physics- (1992-)