# A parallel multi-domain solution methodology applied to nonlinear thermal transport problems in nuclear fuel pins

## Abstract

This paper describes an efficient and nonlinearly consistent parallel solution methodology for solving coupled nonlinear thermal transport problems that occur in nuclear reactor applications over hundreds of individual 3D physical subdomains. Efficiency is obtained by leveraging knowledge of the physical domains, the physics on individual domains, and the couplings between them for preconditioning within a Jacobian Free Newton Krylov method. Details of the computational infrastructure that enabled this work, namely the open source Advanced Multi-Physics (AMP) package developed by the authors is described. Details of verification and validation experiments, and parallel performance analysis in weak and strong scaling studies demonstrating the achieved efficiency of the algorithm are presented. Furthermore, numerical experiments demonstrate that the preconditioner developed is independent of the number of fuel subdomains in a fuel rod, which is particularly important when simulating different types of fuel rods. Finally, we demonstrate the power of the coupling methodology by considering problems with couplings between surface and volume physics and coupling of nonlinear thermal transport in fuel rods to an external radiation transport code.

- Authors:

- Oak Ridge National Laboratory, One Bethel Valley Road, Oak Ridge, TN 37831 (United States)
- Los Alamos National Laboratory, PO Box 1663, Los Alamos, NM 87545 (United States)

- Publication Date:

- OSTI Identifier:
- 22465617

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Journal of Computational Physics; Journal Volume: 286; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 97 MATHEMATICAL METHODS AND COMPUTING; ALGORITHMS; CALCULATION METHODS; COMPUTER CODES; FUEL RODS; HEAT TRANSFER; NONLINEAR PROBLEMS; NUCLEAR FUELS; RADIATION TRANSPORT; TRANSPORT THEORY; VALIDATION

### Citation Formats

```
Philip, Bobby, E-mail: philipb@ornl.gov, Berrill, Mark A., Allu, Srikanth, Hamilton, Steven P., Sampath, Rahul S., Clarno, Kevin T., and Dilts, Gary A.
```*A parallel multi-domain solution methodology applied to nonlinear thermal transport problems in nuclear fuel pins*. United States: N. p., 2015.
Web. doi:10.1016/J.JCP.2015.01.029.

```
Philip, Bobby, E-mail: philipb@ornl.gov, Berrill, Mark A., Allu, Srikanth, Hamilton, Steven P., Sampath, Rahul S., Clarno, Kevin T., & Dilts, Gary A.
```*A parallel multi-domain solution methodology applied to nonlinear thermal transport problems in nuclear fuel pins*. United States. doi:10.1016/J.JCP.2015.01.029.

```
Philip, Bobby, E-mail: philipb@ornl.gov, Berrill, Mark A., Allu, Srikanth, Hamilton, Steven P., Sampath, Rahul S., Clarno, Kevin T., and Dilts, Gary A. Wed .
"A parallel multi-domain solution methodology applied to nonlinear thermal transport problems in nuclear fuel pins". United States.
doi:10.1016/J.JCP.2015.01.029.
```

```
@article{osti_22465617,
```

title = {A parallel multi-domain solution methodology applied to nonlinear thermal transport problems in nuclear fuel pins},

author = {Philip, Bobby, E-mail: philipb@ornl.gov and Berrill, Mark A. and Allu, Srikanth and Hamilton, Steven P. and Sampath, Rahul S. and Clarno, Kevin T. and Dilts, Gary A.},

abstractNote = {This paper describes an efficient and nonlinearly consistent parallel solution methodology for solving coupled nonlinear thermal transport problems that occur in nuclear reactor applications over hundreds of individual 3D physical subdomains. Efficiency is obtained by leveraging knowledge of the physical domains, the physics on individual domains, and the couplings between them for preconditioning within a Jacobian Free Newton Krylov method. Details of the computational infrastructure that enabled this work, namely the open source Advanced Multi-Physics (AMP) package developed by the authors is described. Details of verification and validation experiments, and parallel performance analysis in weak and strong scaling studies demonstrating the achieved efficiency of the algorithm are presented. Furthermore, numerical experiments demonstrate that the preconditioner developed is independent of the number of fuel subdomains in a fuel rod, which is particularly important when simulating different types of fuel rods. Finally, we demonstrate the power of the coupling methodology by considering problems with couplings between surface and volume physics and coupling of nonlinear thermal transport in fuel rods to an external radiation transport code.},

doi = {10.1016/J.JCP.2015.01.029},

journal = {Journal of Computational Physics},

number = ,

volume = 286,

place = {United States},

year = {Wed Apr 01 00:00:00 EDT 2015},

month = {Wed Apr 01 00:00:00 EDT 2015}

}