Publications

Gallis, Michail A.; Torczynski, J.R.; Plimpton, Steven J.; Koehler, Timothy P.

Abstract not provided.

Gallis, Michail A.; Torczynski, J.R.; Plimpton, Steven J.; Koehler, Timothy P.

Abstract not provided.

Gallis, Michail A.; Koehler, Timothy P.; Torczynski, J.R.; Plimpton, Steven J.

Abstract not provided.

Gallis, Michail A.; Koehler, Timothy P.; Torczynski, J.R.; Plimpton, Steven J.

Abstract not provided.

Koehler, Timothy P.; Gallis, Michail A.; Torczynski, J.R.; Plimpton, Steven J.

Abstract not provided.

Plimpton, Steven J.; Gallis, Michail A.

Abstract not provided.

Plimpton, Steven J.; Gallis, Michail A.

Abstract not provided.

Plimpton, Steven J.; Gallis, Michail A.

Abstract not provided.

Gallis, Michail A.; Koehler, Timothy P.; Torczynski, J.R.; Plimpton, Steven J.

Abstract not provided.

Gallis, Michail A.; Koehler, Timothy P.; Torczynski, J.R.; Plimpton, Steven J.

Abstract not provided.

Gallis, Michail A.; Koehler, Timothy P.; Plimpton, Steven J.

This report presents the test cases used to verify, validate and demonstrate the features and capabilities of the first release of the 3D Direct Simulation Monte Carlo (DSMC) code SPARTA (Stochastic Real Time Particle Analyzer). The test cases included in this report exercise the most critical capabilities of the code like the accurate representation of physical phenomena (molecular advection and collisions, energy conservation, etc.) and implementation of numerical methods (grid adaptation, load balancing, etc.). Several test cases of simple flow examples are shown to demonstrate that the code can reproduce phenomena predicted by analytical solutions and theory. A number of additional test cases are presented to illustrate the ability of SPARTA to model flow around complicated shapes. In these cases, the results are compared to other well-established codes or theoretical predictions. This compilation of test cases is not exhaustive, and it is anticipated that more cases will be added in the future.

Gallis, Michail A.; Torczynski, J.R.; Plimpton, Steven J.; Rader, Daniel J.; Koehler, Timothy P.

Abstract not provided.

Gallis, Michail A.; Torczynski, J.R.; Plimpton, Steven J.; Koehler, Timothy P.

Abstract not provided.

Bartel, Timothy J.; Plimpton, Steven J.; Gallis, Michail A.

Icarus is a 2D Direct Simulation Monte Carlo (DSMC) code which has been optimized for the parallel computing environment. The code is based on the DSMC method of Bird[11.1] and models from free-molecular to continuum flowfields in either cartesian (x, y) or axisymmetric (z, r) coordinates. Computational particles, representing a given number of molecules or atoms, are tracked as they have collisions with other particles or surfaces. Multiple species, internal energy modes (rotation and vibration), chemistry, and ion transport are modeled. A new trace species methodology for collisions and chemistry is used to obtain statistics for small species concentrations. Gas phase chemistry is modeled using steric factors derived from Arrhenius reaction rates or in a manner similar to continuum modeling. Surface chemistry is modeled with surface reaction probabilities; an optional site density, energy dependent, coverage model is included. Electrons are modeled by either a local charge neutrality assumption or as discrete simulational particles. Ion chemistry is modeled with electron impact chemistry rates and charge exchange reactions. Coulomb collision cross-sections are used instead of Variable Hard Sphere values for ion-ion interactions. The electro-static fields can either be: externally input, a Langmuir-Tonks model or from a Green's Function (Boundary Element) based Poison Solver. Icarus has been used for subsonic to hypersonic, chemically reacting, and plasma flows. The Icarus software package includes the grid generation, parallel processor decomposition, post-processing, and restart software. The commercial graphics package, Tecplot, is used for graphics display. All of the software packages are written in standard Fortran.