# CASTRO: A NEW COMPRESSIBLE ASTROPHYSICAL SOLVER. II. GRAY RADIATION HYDRODYNAMICS

## Abstract

We describe the development of a flux-limited gray radiation solver for the compressible astrophysics code, CASTRO. CASTRO uses an Eulerian grid with block-structured adaptive mesh refinement based on a nested hierarchy of logically rectangular variable-sized grids with simultaneous refinement in both space and time. The gray radiation solver is based on a mixed-frame formulation of radiation hydrodynamics. In our approach, the system is split into two parts, one part that couples the radiation and fluid in a hyperbolic subsystem, and another parabolic part that evolves radiation diffusion and source-sink terms. The hyperbolic subsystem is solved explicitly with a high-order Godunov scheme, whereas the parabolic part is solved implicitly with a first-order backward Euler method.

- Authors:

- Center for Computational Sciences and Engineering, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)
- Center for Applied Scientific Computing, Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)
- Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

- Publication Date:

- OSTI Identifier:
- 21560316

- Resource Type:
- Journal Article

- Journal Name:
- Astrophysical Journal, Supplement Series

- Additional Journal Information:
- Journal Volume: 196; Journal Issue: 2; Other Information: DOI: 10.1088/0067-0049/196/2/20; Journal ID: ISSN 0067-0049

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTROPHYSICS; DIFFUSION; HYDRODYNAMICS; RADIANT HEAT TRANSFER; ENERGY TRANSFER; FLUID MECHANICS; HEAT TRANSFER; MECHANICS; PHYSICS

### Citation Formats

```
Zhang, W., Almgren, A., Bell, J., Howell, L., and Burrows, A.
```*CASTRO: A NEW COMPRESSIBLE ASTROPHYSICAL SOLVER. II. GRAY RADIATION HYDRODYNAMICS*. United States: N. p., 2011.
Web. doi:10.1088/0067-0049/196/2/20.

```
Zhang, W., Almgren, A., Bell, J., Howell, L., & Burrows, A.
```*CASTRO: A NEW COMPRESSIBLE ASTROPHYSICAL SOLVER. II. GRAY RADIATION HYDRODYNAMICS*. United States. doi:10.1088/0067-0049/196/2/20.

```
Zhang, W., Almgren, A., Bell, J., Howell, L., and Burrows, A. Sat .
"CASTRO: A NEW COMPRESSIBLE ASTROPHYSICAL SOLVER. II. GRAY RADIATION HYDRODYNAMICS". United States. doi:10.1088/0067-0049/196/2/20.
```

```
@article{osti_21560316,
```

title = {CASTRO: A NEW COMPRESSIBLE ASTROPHYSICAL SOLVER. II. GRAY RADIATION HYDRODYNAMICS},

author = {Zhang, W. and Almgren, A. and Bell, J. and Howell, L. and Burrows, A.},

abstractNote = {We describe the development of a flux-limited gray radiation solver for the compressible astrophysics code, CASTRO. CASTRO uses an Eulerian grid with block-structured adaptive mesh refinement based on a nested hierarchy of logically rectangular variable-sized grids with simultaneous refinement in both space and time. The gray radiation solver is based on a mixed-frame formulation of radiation hydrodynamics. In our approach, the system is split into two parts, one part that couples the radiation and fluid in a hyperbolic subsystem, and another parabolic part that evolves radiation diffusion and source-sink terms. The hyperbolic subsystem is solved explicitly with a high-order Godunov scheme, whereas the parabolic part is solved implicitly with a first-order backward Euler method.},

doi = {10.1088/0067-0049/196/2/20},

journal = {Astrophysical Journal, Supplement Series},

issn = {0067-0049},

number = 2,

volume = 196,

place = {United States},

year = {2011},

month = {10}

}