Go on to Section 2.
The Center for Astrophysical Thermonuclear Flashes, or Flash Center, was founded at the University of Chicago in 1997 under contract to the United States Department of Energy as part of its Accelerated Strategic Computing Initiative ((ASC)). The goal of the Center is to solve several problems related to thermonuclear flashes on the surfaces of compact stars (neutron stars and white dwarfs), in particular X-ray bursts, Type Ia supernovae, and novae. To solve these problems requires the participants in the Center to develop new simulation tools capable of handling the extreme resolution and physical requirements imposed by conditions in these explosions, and to do so while making efficient use of the parallel supercomputers developed by the ASC project, the most powerful constructed to date.
The FLASH code represents an important step along the road to this goal. FLASH is a modular, adaptive, parallel simulation code capable of handling general compressible flow problems in astrophysical environments. FLASH has been designed to allow users to configure initial and boundary conditions, change algorithms, and add new physical effects with minimal effort. It uses the PARAMESH library to manage a block-structured adaptive grid, placing resolution elements only where they are needed most. FLASH uses the Message-Passing Interface (MPI) library to achieve portability and scalability on a variety of different message-passing parallel computers.
This user's guide is designed to enable individuals unfamiliar with the FLASH code to quickly get acquainted with its structure and to move beyond the simple test problems distributed with FLASH, customizing it to suit their own needs. The second section briefly describes the equations and algorithms used by the physics modules distributed with FLASH. It assumes that the reader has some familiarity both with the basic physics involved and with numerical hydrodynamics methods. This familiarity is absolutely essential in using FLASH (or any other simulation code) to arrive at meaningful solutions to physical problems. The novice reader is directed to an introductory text such as Patrick Roache's Fundamentals of Computational Fluid Dynamics (Hermosa, 1998) or C. A. J. Fletcher's Computational Techniques for Fluid Dynamics (Springer-Verlag, 1991). The advanced reader who wishes to know more specific information about the various algorithms is directed to the literature references in this section.
The third section discusses how to quickly get started with FLASH, describing how to configure, build, and run the code with one of the included test problems, then examine the resulting output. Users familiar with the capabilities of FLASH who wish to quickly `get their feet wet' with the code can skip directly to this section. The fourth section describes in more detail the use of the configuration and analysis tools distributed with FLASH. The fifth section describes the different test problems distributed with FLASH. The sixth section describes the FLASH code structure at length and gives detailed instructions for extending FLASH's capabilities by adding new problem setups. This section also discusses the code modules included with FLASH 1.0 and describes how new solvers may be integrated into the code. Finally, the seventh section gives guidance on contacting the authors of FLASH.
Go on to Section 2.