Asymptotic analysis of unsteady neutron transport equation

Asymptotic Analysis of Transport Processes

For a large class of processes called transport processes we study in detail a certain asymptotic limit, the diffusion limit. Transport processes arise in linear transport theory, learning theory, nonlinear oscillations in the presence of noise and other problems. We examine closely some examples and give complete proofs for the results stated here.

The diffusion approximation in neutron transport theory – asymptotic expansions

Asymptotic Analysis of Time-dependent Neutron Transport Coupled with Isotopic Depletion and Radioactive Decay

We describe an asymptotic analysis of the coupled nonlinear system of equations describing time-dependent three-dimensional monoenergetic neutron transport and isotopic depletion and radioactive decay. The classic asymptotic diffusion scaling of Larsen and Keller [1], along with a consistent small scaling of the terms describing the radioactive decay of isotopes, is applied to this coupled nonl...

Sediment Transport in Unsteady Flow Conditions

Sediment transport under unsteady flow condition is studied experimentally. In the first step, sediment transport under different steady flow conditions was measured and an empirical equation was derived for its calculation. In the next step, two continuous and three stepwise hydrographs were generated in the flume, and their sediment transport rate was measured. The continuous hydrographs were...

Homogenization of the criticality spectral equation in neutron transport

We address the homogenization of an eigenvalue problem for the neutron transport equation in a periodic heterogeneous domain, modeling the criticality study of nuclear reactor cores. We prove that the neutron flux, corresponding to the first and unique positive eigenvector, can be factorized in the product of two terms, up to a remainder which goes strongly to zero with the period. One term is ...