DEFAULT OTHER OPTIONS
- single precision -enable-dp (double precision)
- optimization of -O -enable-debug, -enable-mips2,
-enable-mips3, -enable-mips4
- installdir = chimeraxxx/bin -installdir=DIR
- installalldir = /usr/local -installalldir=DIR
update (compiles everything, CMD=install, CMD=installall,
and leaves them in chimeraxxx/src) CMD=clean (rm temporary files),
CMD=clobber (rm executables, .f, .a)
setenv SCRIPTLIB $HOME/chimeraxxx/scriptlib where the above path matches the location of your chimeraxxx directory. Use "echo $SCRIPTLIB" to test for the correct assignment. This is necessary for seamless access to the library of routines in this directory.
Chimera Grid Tools (CGT) is a software package containing a variety of tools for the Chimera overset grid approach [1] for solving complex configuration problems. Several examples of recent computations that used Chimera Grid Tools for the creation of the grid systems are shown on Figure 1. The current procedure for performing overset CFD analysis on such configurations is outlined in Figure 2. A typical starting point is a description of the surface geometry in CAD format, while typical outputs from the process are force and moment coefficients, pressure distributions, etc. of the configuration under certain specified free stream conditions. The complete suite of tools necessary to perform such a process includes CAD tools for geometry manipulation, and geometry defects elimination, Chimera Grid Tools for grid generation and post-processing, PEGSUS [2], DCF3D [3,4], (or other equivalent tool) for domain connectivity, OVERFLOW [5] for solution computation, and FOMOCO Utilities [6, 7] for force and moment computation. Individual tools used in various parts of the process are illustrated in red in Figure 2.
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V-22 Tiltrotor (Robert L. Meakin, Army Aeroflightdynamics Directorate) |
|---|---|
 |
Comanche (Robert L. Meakin, Army Aeroflightdynamics Directorate) |
 |
X-38 Crew Return Vehicle under B-52 Captive Carry (James S. Greathouse, NASA Johnson Space Center) |
 |
Trapezoidal Wing High-Lift Configuration (Steven M. Nash, MCAT, Inc., NASA Ames Research Center) |
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Generic Amphibious Assault Vehicle (Donovan L. Mathias, MCAT, Inc., NASA Ames Research Center) |
Tools in CGT can be grouped into the following categories: surface grid generation tools, volume grid generation tools, grid utilities, configuration automation scripts, utility scripts, and post-processing tools. See Table 1 below for a brief description of each tool, the category for which it resides, and access to more detailed documentation. The package is organized with the following directories:
The bin directory contains a number of Tcl scripts which can automate the building of an overset grid system following the process illustrated in Figure 2. These scripts will build input files, execute, and provide error checking for a number of programs, including: volume grid generation ( HYPGEN [8, 9] and LEGRID), volume grid smoothing ( SMOGRD), domain connectivity using PEGASUS 5.0 (complete input file) or PEGSUS 4.1 (partial input file) [2], surface fringe point projection ( PROGRD), hybrid surface grid generation for force and moment computation [6, 7], flow solution computation using OVERFLOW [5]. See the scripts manual for more details. Such scripts have been used to create complex grid systems for high-lift configurations [10].
The doc directory contains documentation and sample input files for the various grid tools and scripts, as well as a log of the changes made for each release of CGT.
The examples directory contains a suite of examples to test the tools, and also includes a self-verification tool named verify to check that the tools are running properly.
The gui directory contains files for a graphical user interface called OVERGRID [11, 12] that can be used to access the various grid tools. For a user facing a new problem, it is much easier to perform grid generation with the assistance of a graphical tool for the first time. Once the gridding strategy has been identified, scripts can be constructed to generate grids for similar configurations.
The include directory contains header files that are included into various source code files through use of the preprocessor.
The lib directory contains a library of FORTRAN routines that are common to many of the grid tools. These routines include computation of stretching functions, computation of grid normals, projections of grids, grid topology determination and enforcement, and many others.
The scriptlib directory contains a library of Tcl language script procedures that are called by some of the scripts in the bin directory, and are available to the user by using the lappend auto_path scriptlib command.
The src directory contains the source code for the high-level batch-mode FORTRAN codes that can be run by the user.
Below is a figure showing the hierarchy of the various modules in the Chimera Grid Tools package:
 |
OVERGRID - Graphical user interface for geometry/grid visualization and access to various grid modules |
|---|
| Color | Category | Color | Category |
|---|---|---|---|
| - | Surface Grid Generation | - | Volume Grid Generation |
| - | Grid Utility | - | Configuration Automation Script |
| - | Utility Script | - | Post Processing |
| Program | Description |
|---|---|
| boxgr | Generation of stretched cartesian background grids and elliptic far-field grids |
| BuildIngrid | Builds the INGRID file used by PEGSUS 4.1 |
| BuildMixsuri | Builds the MIXSUR/OVERINT input file from OVERFLOW input files |
| BuildOveri | Builds the OVERFLOW input files from individual "stubs" |
| BuildPegi/BuildPeg5i | Builds the PEGSUS 4.1/5.0 input file template (no hole boundaries for 4.1) |
| BuildPlot | Creates a PLOT3D command file to view family/boundary condition/etc. info |
| BuildProgrdi | Builds the PROGRD input file from the OVERFLOW input file information |
| BuildSurf | Runs 'make' for each component grid to update configuration surface grids |
| BuildVol | Creates volume grids via either makevol or boxgr |
| cgtclean | Cleans output from most CGT tools |
| collar | Script to create collar grids [13] |
| compx | Computation of difference between two grids |
| conmug | Auto-concatenation of multiple surface and curve grids |
| extractsrf | Parses MIXSUR input file to create SPLITMX/SPLITMQ inputs for just surface info |
| grided | Compilation of a variety of grid editing functions for structured grids |
| gridinf | Computes basic grid information |
| hypgen | Generation of a hyperbolic volume grid from a single surface grid [8, 9] |
| hypin | Generation of normal spacing function for volume grids |
| intersect | Runs the lsect program, establishing filenames from command line inputs |
| intgrd | Generation of a new surface grid onto a reference grid via interpolation |
| loadis | Computation of sectional force coefs on components |
| lsect | Find a line of points representing the intersection of two surface grids |
| makevol | Creates a volume grid via HYPGEN/LEGRID, and runs SMOGRD using OVERFLOW input file |
| minterp | Interpolation of single/multiple grid and solution files |
| PreVol | Builds OVERFLOW input files, config.tcl, inputs.tcl from surface grid file |
| plothole | Creates PLOT3D command file for PEGSUS 4.1 boundaries |
| progrd | Projection of points onto a collection of reference grids |
| recurv | Grid-point redistribution |
| RunPeg/RunPeg5 | Runs BuildIngrid, pegsus41/pegasus50, and PROGRD using configuration information |
| sblock | Partial surface domain decomposition and grid generation [14] |
| ScriptClean | Cleans up .srf, .vol, .mvlog, etc. files for an entire configuration |
| seamcr | Automatic seam curve extraction and spider web grid generation [15] |
| seamcrt | Surface curves creation on surface triangulations |
| shftgrd | Shifting/translating grid coordinates of a specified subset |
| smogrd | Perform elliptic smoothing in selected grid subset to spread out region of fine spacing |
| smooth | Smooth grid by performing second order smoothing |
| smosurf | Perform grid spacing smoothing in one direction for volume grids |
| splitmx | Extraction of arbitrary grid subsets from PLOT3D multiple grid file |
| splitmq | Extraction of arbitrary q subsets from PLOT3D multiple grid q file |
| srap | Perform splining, grid point redistribution and projection on curves/surfaces |
| strchk | Computation and display of local stretching ratio info for grids |
| stretch | Evaluation and display of 1D stretching functions |
| surgrd | Generation of a new surface grid onto a collection of reference grids via hyperbolic/algebraic surface grid generation [16] |
| triged | Compilation of a variety of grid editing functions for surface triangulations |
| vpro | Interpolate velocity profiles from a grid and solution at specified surface normals or lines |
| wingcap | Generation of surface grid in tip region of wing |
| wkcut | Generation of surface grid in wake region |
Many people have contributed to the different parts of Chimera Grid Tools. A summary of the tools/scripts and their application is shown in Table 1. See the documentation for the individual tool to determine authorship. Questions and suggestions can be directed to the corresponding authors (see Table 2).
| Name | Affiliation |
|---|---|
| Pieter G. Buning | LaRC |
| William M. Chan | MCAT, Inc., ARA, ARC | Steven M. Nash | MCAT, Inc., AIC, ARC | Stuart E. Rogers | AIC, ARC |
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