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U.S. Department of Energy
Office of Scientific and Technical Information

APACHE: a generalized-mesh Eulerian computer code for multicomponent chemically reactive fluid flow

Technical Report ·
DOI:https://doi.org/10.2172/6421504· OSTI ID:6421504

The APACHE computer code has been developed to solve the equations of transient multicomponent chemically reactive fluid dynamics. APACHE is a time-marching finite-difference code that can be run in a purely explicit mode or a partially implicit (ICE) mode. The governing equations are written in two-dimensional variable-depth form. This description includes planar and cylindrical geometries as special cases. Spatial differences are written in conservative form wherever possible, using a generalized two-dimensional Eulerian mesh that allows convenient representation of curved boundaries and provides variable zoning. A new difference approximation to the convective terms, the tensor viscosity method, is used to achieve numerical stability without excessive numerical damping. Multicomponent diffusion is calculated by a self-consistent effective binary diffusion algorithm. APACHE contains a spatial marching option that greatly reduces computer time for steady-state supersonic flow calculations. For CW chemical laser applications, radiation intensities and laser power are calculated. The radiation intensities are fully coupled to the fluid, so that threshold, cutoff, and J-shifting occur automatically. Complete descriptions of the APACHE methodology, the code structure, and the procedure for setting up problems are provided. A FORTRAN listing of the code is given in an appendix.

Research Organization:
Los Alamos Scientific Lab., NM (USA)
DOE Contract Number:
W-7405-ENG-36
OSTI ID:
6421504
Report Number(s):
LA-7427
Country of Publication:
United States
Language:
English