Numerical optimization of a multiphysics calculation scheme based on partial convergence

Cattaneo, Paolo; Lenain, Roland; Merle, E.; Patricot, Cyril; Schneider, Didier

doi:10.1016/j.anucene.2020.107892

Cited by 7 publications

(4 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Te boundary conditions are listed in Table 2. Te reactor power is set to be 200 MW in equation (2). Figure 3 shows the numerical calculation result of physics distribution under the boundary condition of a coolant inlet velocity of 4 m/s and inlet temperature of 270℃.…”

Section: Problem Description and Sampling Designmentioning

confidence: 99%

“…Several coupling algorithms have been developed to solve this large-scale neutronics/thermal-hydraulics nonlinear system. Picard iteration is the most common method since it could fully reuse the existing codes for individual physics [1][2][3]. Specifcally, in Picard iteration, the coupling boundary information is exchanged between diferent physical felds to consider the coupling efect, while each physical feld is still solved by the original existing code.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A Reduced Order Model Based on ANN-POD Algorithm for Steady-State Neutronics and Thermal-Hydraulics Coupling Problem

Liu

Han

2023

Science and Technology of Nuclear Installations

View full text Add to dashboard Cite

The neutronics and thermal-hydraulics (N/TH) coupling behavior analysis is a key issue for nuclear power plant design and safety analysis. Due to the high-dimensional partial differential equations (PDEs) derived from the N/TH system, it is usually time consuming to solve such a large-scale nonlinear equation by the traditional numerical solution method of PDEs. To solve this problem, this work develops a reduced order model based on the proper orthogonal decomposition (POD) and artificial neural networks (ANNs) to simulate the N/TH coupling system. In detail, the POD method is used to extract the POD modes and corresponding coefficients from a set of full-order model results under different boundary conditions. Then, the backpropagation neural network (BPNN) is utilized to map the relationship between the boundary conditions and POD coefficients. Therefore, the physical fields under the new boundary conditions could be calculated by the predicated POD coefficients from ANN and POD modes from snapshot. In order to assess the performance of an ANN-POD-based reduced order method, a simplified pressurized water reactor model under different inlet coolant temperatures and inlet coolant velocities is utilized. The results show that the new reduced order model can accurately predict the distribution of the physical fields, as well as the effective multiplication factor in the N/TH coupling nuclear system, whose relative errors are within 1%.

show abstract

Section: Problem Description and Sampling Designmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A Reduced Order Model Based on ANN-POD Algorithm for Steady-State Neutronics and Thermal-Hydraulics Coupling Problem

Liu

Han

2023

Science and Technology of Nuclear Installations

View full text Add to dashboard Cite

show abstract

“…For instance, considering an accidental scenario such as the unprotected loss of flow (ULOF) for SFR, neutronics and thermal hydraulics are coupled together to perform a large number of parametric computations on relevant quantities pertaining to the safety of the reactor. Recently, much work has been dedicated to the coupling strategy to improve its convergence as illustrated in [1][2][3]. In the case of severe accidents, it has been observed that in these simulations, neutron transport is still a bottleneck in terms of computational times, with more than 80% of the total simulation time [4].…”

Section: Introductionmentioning

confidence: 99%

“…Comparison of absorption rates with respect to reference values for the 3D configuration for the MP cases such that k = l ∈ [[1,4]] (cf. comments in text on coloured lines).…”

mentioning

confidence: 99%

Design and Application of DG-FEM Basis Functions for Neutron Transport on Two-Dimensional and Three-Dimensional Hexagonal Meshes

Calloo,

Labeurthre,

Le Tellier

2024

JNE

View full text Add to dashboard Cite

Reactor design requires safety studies to ensure that the reactors will behave appropriately under incidental or accidental situations. Safety studies often involve multiphysics simulations where several branches of reactor physics are necessary to model a given phenomenon. In those situations, it has been observed that the neutron transport part is still a bottleneck in terms of computational times, with more than 80% of the total time. In the case of hexagonal lattice reactors, transport solvers usually invert the discretised Boltzmann equation by discretising the regular hexagon into lozenges or triangles. In this work, we seek to reduce the computational burden of the neutron transport solver by designing a numerical spatial discretisation scheme that would be more appropriate for honeycomb meshes. In our past research efforts, we have set up interesting discretisation schemes in the finite element setting in 2D, and we wish to extend them to 3D geometries that are prisms with a hexagonal base. In 3D, a rigorous method was derived to shrink the tensor product between 2D and 1D bases to minimum terms. We have applied these functions successfully on a reactor benchmark—Takeda Model 4—to compare and contrast the numerical results in a physical setting.

show abstract

A multi-level nonlinear elimination-based JFNK method for multi-scale multi-physics coupling problem in pebble-bed HTR

Liu

Zhang

et al. 2022

Annals of Nuclear Energy

View full text Add to dashboard Cite

Numerical optimization of a multiphysics calculation scheme based on partial convergence

Cited by 7 publications

References 24 publications

A Reduced Order Model Based on ANN-POD Algorithm for Steady-State Neutronics and Thermal-Hydraulics Coupling Problem

A Reduced Order Model Based on ANN-POD Algorithm for Steady-State Neutronics and Thermal-Hydraulics Coupling Problem

Design and Application of DG-FEM Basis Functions for Neutron Transport on Two-Dimensional and Three-Dimensional Hexagonal Meshes

A multi-level nonlinear elimination-based JFNK method for multi-scale multi-physics coupling problem in pebble-bed HTR

Contact Info

Product

Resources

About