## MAESTRO: Low Mach Number Astrophysics## OverviewAs part of the SciDAC Computational Astrophysics Consortium we have developed a new low Mach number hydrodynamics code, MAESTRO, that includes stellar equations of state and nuclear reaction networks. We are currently using MAESTRO to study the convective phase of Type Ia supernovae and Type I X-ray bursts. Development of MAESTRO is in collaboration with Mike Zingale at Stony Brook Univeristy. ## MAESTRO DownloadTo get a copy of the latest version of theMAESTRO repository using git, please visit our
Downloads page.
## MAESTRO Email Support ListIf you are interested in using MAESTRO, please join our MAESTRO mailing list to receive any updates and see questions other users are asking: https://groups.google.com/forum/#!forum/maestro-help .
## Why A Low Mach Number Approach?A large number of interesting astrophysical phenomena occur in the low
Mach number regime, where the characteristic fluid velocity is small compared to
the speed of sound. Evolving these flows with a fully compressible
simulation code is inefficient because these codes compute the effect
of sound waves, which are unimportant for our problems of interest. Δ t < min { Δ x / (|u| + c) } Δ t ~ Δ x / c for an interface moving at a Mach number M << 1,
it takes 1/M timesteps for that interface to move just one zone!
Our desire is to reformulate the equations of hydrodynamics to
filter out sound waves, while retaining the compressibility effects
important to the problem at hand. This will result in a timestep
constraint of the form Δ t < min{ Δ x / |u| } ## MAESTRO Features## Coordinate SystemsMAESTRO supports calculations in 2D and 3D Cartesian coordinates.## Unsplit PPM HydrodynamicsMAESTRO uses an unsplit version of the piecewise parabolic method (PPM), with new limiters that avoid reducing the accuracy of the scheme at smooth extrema.## Modular Equation of State and Reaction NetworksMAESTRO is written in a modular fashion so that the routines for the equation of state and reaction network can be supplied by the user. The reactions are included in the time integration scheme in a second-order accurate operator-split formulation (Strang splitting).## AMR in MAESTROOur approach to adaptive refinement in MAESTRO uses a nested hierarchy of logically-rectangular grids with refinement of the grids only in space, i.e. all levels are advanced with the same time step. The integration algorithm on the grid hierarchy is such that each substep of a time step is completed at all levels before proceding to the next substep. Data is synchronized between levels at the completion of each substep.During the regridding step, increasingly finer grids are recursively embedded in coarse grids until the solution is sufficiently resolved. An error estimation procedure based on user-specified criteria evaluates where additional refinement is needed and grid generation procedures dynamically create or remove rectangular fine grid patches as resolution requirements change. ## Visualization## Software FrameworkThe MAESTRO software is written in the Fortran90BoxLib
software framework developed by CCSE.## Questions?Contact Ann Almgren.
## MAESTRO-related Publications
M. Zingale, C. M. Malone, A. Nonaka, A. S. Almgren, and J. B. Bell,
A.M. Jacobs, M. Zingale, A. Nonaka, A.S. Almgren, J.B. Bell,
M. Zingale, A. Nonaka, A. S. Almgren, J. B. Bell, C. Malone, and R. Orvedahl,
Ann Almgren, John Bell, Andy Nonaka and Michael Zingale,
C. M. Malone, M. Zingale, A. Nonaka, A. S. Almgren, and J. B. Bell,
C. Gilet, A.S. Almgren, J.B. Bell, A. Nonaka, S.E. Woosley and M. Zingale,
A. Nonaka, A. J. Aspden, M. Zingale, A. S. Almgren, J. B. Bell, and S. E. Woosley,
M. Zingale, A. Nonaka, A. S. Almgren, J. B. Bell, C. M. Malone, and S. E. Woosley,
A. Nonaka, A. S. Almgren, J. B. Bell, H. Ma, S. E. Woosley, and M. Zingale,
C. M. Malone, A. Nonaka, A. S. Almgren, J. B. Bell, and M. Zingale
Astrophysical Journal, 728, 118, Feb. 2011.
[arxiv]
A. Almgren, J. Bell, D. Kasen, M. Lijewski, A. Nonaka, P. Nugent, C. Rendleman, R. Thomas, M. Zingale,
H. Ma, M. Zingale, S. E. Woosley, A. J. Aspden, J. B. Bell, A. S. Almgren,
A. Nonaka, and S. Dong,
A. Nonaka, A. S. Almgren, J. B. Bell, M. J. Lijewski, C. M. Malone, and M. Zingale,
M. Zingale, A. S. Almgren, J. B. Bell, A. Nonaka, and S. E. Woosley,
S. E. Woosley, A. S. Almgren, A. J. Aspden, J. B. Bell,
D. Kasen, A. R. Kerstein, H. Ma, A. Nonaka, and M. Zingale,
A. S. Almgren, J. B. Bell, A. Nonaka, M. Zingale,
M. Zingale, A. S. Almgren, J. B. Bell, C. M. Malone and A. Nonaka,
A. S. Almgren, J. B. Bell, and M. Zingale,
A. S. Almgren, J. B. Bell, A. Nonaka, and M. Zingale,
A. S. Almgren, J. B. Bell, C. A. Rendleman, and M. Zingale,
A. S. Almgren, J. B. Bell, C. A. Rendleman, and M. Zingale,
## AcknowledgementsThis work was supported by the SciDAC Program of the DOE Office of Mathematics, Information, and Computational Sciences under the U.S. Department of Energy under contract No. DE-AC02-05CH11231 to LBNL and by a DOE Office of Nuclear Physics Outstanding Junior Investigator award (No. DE-FG02-06ER41448) to Mike Zingale at Stony Brook Univeristy. |