Coupling Methods for HTR-PM Multicircuit Problem

Jianan Lu, Jiong Guo, Tomasz Kozlowski, Fu Li

Research output: Contribution to journalArticle

Abstract

The High-Temperature Gas-Cooled Reactor–Pebble Bed Module (HTR-PM) is a large-scale complex system that includes reactor core, steam generator, helium circulator, and other important components. When integrating these components, coupling problems such as multiphysics problem, multicircuit problem, multiscale problem, and multimodule problem arise in the numerical simulation. The HTR-PM multicircuit system comprises the primary circuit and secondary circuit, which are simulated by two independent codes and coupled by the interface in the once-through steam generator. Although time-consuming, Picard iteration is a feasible and convenient coupling method to integrate two components because oversolving in the early stages of the iteration causes strong fluctuation between circuits. To address this problem, optimization of the maximum subiteration number and convergence precision have been implemented to improve the efficiency and numerical stability of the Picard iteration. The Dynamic Residual Balance method, an improved version of the Residual Balance method, is proposed to prevent oversolving inside the subiterations. It takes into consideration fluctuation between circuits, and this method is robust in a wide range of cases. Moreover, the nonlinear preconditioned Jacobian-Free Newton-Krylov method, which has less fluctuation between circuits than Picard iteration, is a coupling scheme that updates all the solution variables from the primary circuit and the secondary circuit simultaneously. Outstanding convergence and efficiency can be obtained by implementing the proper preconditioner in this HTR-PM multicircuit problem. The downside is that it requires significant modification to the legacy codes.

Original languageEnglish (US)
Pages (from-to)131-146
Number of pages16
JournalNuclear Science and Engineering
Volume193
Issue number1-2
DOIs
StatePublished - Feb 1 2019

Fingerprint

Networks (circuits)
Steam generators
Reactor cores
Convergence of numerical methods
Newton-Raphson method
Helium
Large scale systems
Computer simulation
Gases
Temperature

Keywords

  • Dynamic Residual Balance method
  • HTR-PM
  • Jacobian-Free Newton-Krylov method
  • Picard iteration
  • multicircuit

ASJC Scopus subject areas

  • Nuclear Energy and Engineering

Cite this

Coupling Methods for HTR-PM Multicircuit Problem. / Lu, Jianan; Guo, Jiong; Kozlowski, Tomasz; Li, Fu.

In: Nuclear Science and Engineering, Vol. 193, No. 1-2, 01.02.2019, p. 131-146.

Research output: Contribution to journalArticle

Lu, Jianan ; Guo, Jiong ; Kozlowski, Tomasz ; Li, Fu. / Coupling Methods for HTR-PM Multicircuit Problem. In: Nuclear Science and Engineering. 2019 ; Vol. 193, No. 1-2. pp. 131-146.
@article{f885e78cbd9f4567b5cf015c2febf47d,
title = "Coupling Methods for HTR-PM Multicircuit Problem",
abstract = "The High-Temperature Gas-Cooled Reactor–Pebble Bed Module (HTR-PM) is a large-scale complex system that includes reactor core, steam generator, helium circulator, and other important components. When integrating these components, coupling problems such as multiphysics problem, multicircuit problem, multiscale problem, and multimodule problem arise in the numerical simulation. The HTR-PM multicircuit system comprises the primary circuit and secondary circuit, which are simulated by two independent codes and coupled by the interface in the once-through steam generator. Although time-consuming, Picard iteration is a feasible and convenient coupling method to integrate two components because oversolving in the early stages of the iteration causes strong fluctuation between circuits. To address this problem, optimization of the maximum subiteration number and convergence precision have been implemented to improve the efficiency and numerical stability of the Picard iteration. The Dynamic Residual Balance method, an improved version of the Residual Balance method, is proposed to prevent oversolving inside the subiterations. It takes into consideration fluctuation between circuits, and this method is robust in a wide range of cases. Moreover, the nonlinear preconditioned Jacobian-Free Newton-Krylov method, which has less fluctuation between circuits than Picard iteration, is a coupling scheme that updates all the solution variables from the primary circuit and the secondary circuit simultaneously. Outstanding convergence and efficiency can be obtained by implementing the proper preconditioner in this HTR-PM multicircuit problem. The downside is that it requires significant modification to the legacy codes.",
keywords = "Dynamic Residual Balance method, HTR-PM, Jacobian-Free Newton-Krylov method, Picard iteration, multicircuit",
author = "Jianan Lu and Jiong Guo and Tomasz Kozlowski and Fu Li",
year = "2019",
month = "2",
day = "1",
doi = "10.1080/00295639.2018.1504545",
language = "English (US)",
volume = "193",
pages = "131--146",
journal = "Nuclear Science and Engineering",
issn = "0029-5639",
publisher = "American Nuclear Society",
number = "1-2",

}

TY - JOUR

T1 - Coupling Methods for HTR-PM Multicircuit Problem

AU - Lu, Jianan

AU - Guo, Jiong

AU - Kozlowski, Tomasz

AU - Li, Fu

PY - 2019/2/1

Y1 - 2019/2/1

N2 - The High-Temperature Gas-Cooled Reactor–Pebble Bed Module (HTR-PM) is a large-scale complex system that includes reactor core, steam generator, helium circulator, and other important components. When integrating these components, coupling problems such as multiphysics problem, multicircuit problem, multiscale problem, and multimodule problem arise in the numerical simulation. The HTR-PM multicircuit system comprises the primary circuit and secondary circuit, which are simulated by two independent codes and coupled by the interface in the once-through steam generator. Although time-consuming, Picard iteration is a feasible and convenient coupling method to integrate two components because oversolving in the early stages of the iteration causes strong fluctuation between circuits. To address this problem, optimization of the maximum subiteration number and convergence precision have been implemented to improve the efficiency and numerical stability of the Picard iteration. The Dynamic Residual Balance method, an improved version of the Residual Balance method, is proposed to prevent oversolving inside the subiterations. It takes into consideration fluctuation between circuits, and this method is robust in a wide range of cases. Moreover, the nonlinear preconditioned Jacobian-Free Newton-Krylov method, which has less fluctuation between circuits than Picard iteration, is a coupling scheme that updates all the solution variables from the primary circuit and the secondary circuit simultaneously. Outstanding convergence and efficiency can be obtained by implementing the proper preconditioner in this HTR-PM multicircuit problem. The downside is that it requires significant modification to the legacy codes.

AB - The High-Temperature Gas-Cooled Reactor–Pebble Bed Module (HTR-PM) is a large-scale complex system that includes reactor core, steam generator, helium circulator, and other important components. When integrating these components, coupling problems such as multiphysics problem, multicircuit problem, multiscale problem, and multimodule problem arise in the numerical simulation. The HTR-PM multicircuit system comprises the primary circuit and secondary circuit, which are simulated by two independent codes and coupled by the interface in the once-through steam generator. Although time-consuming, Picard iteration is a feasible and convenient coupling method to integrate two components because oversolving in the early stages of the iteration causes strong fluctuation between circuits. To address this problem, optimization of the maximum subiteration number and convergence precision have been implemented to improve the efficiency and numerical stability of the Picard iteration. The Dynamic Residual Balance method, an improved version of the Residual Balance method, is proposed to prevent oversolving inside the subiterations. It takes into consideration fluctuation between circuits, and this method is robust in a wide range of cases. Moreover, the nonlinear preconditioned Jacobian-Free Newton-Krylov method, which has less fluctuation between circuits than Picard iteration, is a coupling scheme that updates all the solution variables from the primary circuit and the secondary circuit simultaneously. Outstanding convergence and efficiency can be obtained by implementing the proper preconditioner in this HTR-PM multicircuit problem. The downside is that it requires significant modification to the legacy codes.

KW - Dynamic Residual Balance method

KW - HTR-PM

KW - Jacobian-Free Newton-Krylov method

KW - Picard iteration

KW - multicircuit

UR - http://www.scopus.com/inward/record.url?scp=85053423653&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85053423653&partnerID=8YFLogxK

U2 - 10.1080/00295639.2018.1504545

DO - 10.1080/00295639.2018.1504545

M3 - Article

AN - SCOPUS:85053423653

VL - 193

SP - 131

EP - 146

JO - Nuclear Science and Engineering

JF - Nuclear Science and Engineering

SN - 0029-5639

IS - 1-2

ER -