Abstract
The paper considers the problems of calculating the stationary transport of high-energy neutrons from an external source in a hollow metal structure. The spatial grid for calculation consists of tetrahedra, which allows to model complicated geometric shapes of objects. The calculated area is highly heterogeneous, since it consists of metal parts with strong absorption and scattering and practically non-absorbing internal parts. A scheme based on a minimal stencil, within a single tetrahedron for the calculation. The scheme has a high approximation order and is based on characteristic approaches. For a smooth solution and a constant absorption coefficient in each cell, the scheme has a third order of convergence. The cells are traversed using the graph topological sorting algorithm. A new version of the parallelization of the calculation for the OpenMP standard has been proposed. For discretization by an angular variable, a cubature formula of the direct product type over two angles with an algebraic order of accuracy of nine is used. The angular grid is constructed in such a way as to correctly calculate the moments for narrowly directed beams of external radiation. The standard 26-group approximation of the BNAB library is used for energy sampling. A decrease in the neutron flux inside the structure is shown for groups with an energy above 1 MeV. Graphs of the angular distribution inside the structure are given.
Publisher
Keldysh Institute of Applied Mathematics
Reference12 articles.
1. Г.О. Астафуров, “Построение и исследование метода CPP (Cubic Polynomial Projection) решения уравнения переноса”, Препринты ИПМ им. М.В. Келдыша, 2022, №66, 56с. https://doi.org/10.20948/prepr-2022-66 https://library.keldysh.ru/preprint.asp?id=2022-66
2. Е.Н. Аристова, Г.О. Астафуров, “Проекционно-характеристический метод третьего порядка для решения уравнения переноса на неструктурированных сетках”, Матем. моделирование, 35:11 (2023), 79–93
3. Е.Н. Аристова, Г.О. Астафуров, "Метод коротких характеристик второго порядка для решения уравнения переноса на сетке из тетраэдров", Матем. моделирование, 28:7 (2016), 20-30
4. Math. Models Comput. Simul., 9:1 (2017), 40-47
5. Е.Н. Аристова, Г.О. Астафуров, "Характеристическая схема для решения уравнения переноса на неструктурированной сетке с барицентрической интерполяцией", Матем. моделирование, 30:9 (2018), 33-50