The CFD Utility Software Library, a.k.a. CFDTOOLS, contains nearly 30 numerical analysis libraries and close to 100 utility applications built upon those libraries. These utilities were developed over a roughly fifty year span to support aerospace research and development activities at NASA Ames Research Center (ARC). They are mostly written in Fortran 90 or 77 and are designed with potential reuse in mind. The library also includes C translations of roughly a dozen numerics routines in the C_utilities module.

The library began as the ARC Aerodynamics Division Software Library, and is currently maintained by ARC Entry Systems and Technology Division. David Saunders and Robert Kennelly are the primary authors, with miscellaneous contributions from many others over the years. CFDTOOLS is expected to grow slowly as new functionality is required.

• Single-function tools for manipulating multiblock grids and flow solutions
• Rapid searching/interpolation for structured or unstructured grids (ADT methods)
• Automated gridding for axisymmetric capsules with curvature-based discretization
• Generic optimization frameworks with various applications
• General-purpose numerics subroutines and character-manipulation subroutines

A detailed summary of each library/application is provided below.

• [email protected]
• [email protected]

The CFDTOOLS software archive is available for download on NASA's public Github. The software may be cloned using git in the typical fashion:

git clone https://www.github.com/nasa/cfdtools.git

Once downloaded, the software is compiled and installed using CMake. The software has no dependencies, and is known to build successfully using relatively recent compilers from Intel and GNU on Ubuntu and SUSE Linux. The basic installation process is as follows:

cd <cfdtools_source_dir>
mkdir build && cd build
cmake -DCMAKE_INSTALL_PREFIX=<cfdtools_install_dir> ..
cmake --build .
cmake --install .

Upon installation, all that is required to use the CFDTOOLS applications is to add <cfdtools_install_dir>/bin to the PATH environment variable. If you are building software that links against the CFDTOOLS library using CMake, simply add -DCMAKE_PREFIX_PATH=<cfdtools_install_dir> to the initial CMake configuration command for your project. Then, in your projects CMakeLists.txt, add the following:

find_package(cfdtools REQUIRED)

add_executable(my_program ...)
target_link_libraries(my_program cfdtools::<libname>)

CFDTOOLS also supports direct inclusion as a project submodule using CMake's add_subdirectory command.

This software is released under the NASA Open Source Agreement Version 1.3.

To contribute to this software package we require that non-NASA authors assign their rights in the contributed code to NASA. Contributor License Agreements (CLAs) are available in the contrib folder.

Copyright 2021 United States Government as represented by the Administrator of the National Aeronautics and Space Administration. No copyright is claimed in the United States under Title 17, U.S. Code. All Other Rights Reserved.

No Warranty: THE SUBJECT SOFTWARE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY OF ANY KIND, EITHER EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY THAT THE SUBJECT SOFTWARE WILL CONFORM TO SPECIFICATIONS, ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR FREEDOM FROM INFRINGEMENT, ANY WARRANTY THAT THE SUBJECT SOFTWARE WILL BE ERROR FREE, OR ANY WARRANTY THAT DOCUMENTATION, IF PROVIDED, WILL CONFORM TO THE SUBJECT SOFTWARE. THIS AGREEMENT DOES NOT, IN ANY MANNER, CONSTITUTE AN ENDORSEMENT BY GOVERNMENT AGENCY OR ANY PRIOR RECIPIENT OF ANY RESULTS, RESULTING DESIGNS, HARDWARE, SOFTWARE PRODUCTS OR ANY OTHER APPLICATIONS RESULTING FROM USE OF THE SUBJECT SOFTWARE. FURTHER, GOVERNMENT AGENCY DISCLAIMS ALL WARRANTIES AND LIABILITIES REGARDING THIRD-PARTY SOFTWARE, IF PRESENT IN THE ORIGINAL SOFTWARE, AND DISTRIBUTES IT "AS IS."

Waiver and Indemnity: RECIPIENT AGREES TO WAIVE ANY AND ALL CLAIMS AGAINST THE UNITED STATES GOVERNMENT, ITS CONTRACTORS AND SUBCONTRACTORS, AS WELL AS ANY PRIOR RECIPIENT. IF RECIPIENT'S USE OF THE SUBJECT SOFTWARE RESULTS IN ANY LIABILITIES, DEMANDS, DAMAGES, EXPENSES OR LOSSES ARISING FROM SUCH USE, INCLUDING ANY DAMAGES FROM PRODUCTS BASED ON, OR RESULTING FROM, RECIPIENT'S USE OF THE SUBJECT SOFTWARE, RECIPIENT SHALL INDEMNIFY AND HOLD HARMLESS THE UNITED STATES GOVERNMENT, ITS CONTRACTORS AND SUBCONTRACTORS, AS WELL AS ANY PRIOR RECIPIENT, TO THE EXTENT PERMITTED BY LAW. RECIPIENT'S SOLE REMEDY FOR ANY SUCH MATTER SHALL BE THE IMMEDIATE, UNILATERAL TERMINATION OF THIS AGREEMENT.

C = CFD, G = General Numerics, P = Programming Tool

• Aug 30 2013: Initial preparation.
• Sep 20 2013: Initial summary uploads to SourceForge.
• Sep 30 2013: Still awaiting final NASA approval to upload software.
• Oct 17 2013: CAPSULE_GRID document uploaded following 2.5-week government shutdown hiatus.
• Oct 22 2013: Folders for all libraries are now set up with subroutine one- liner READMEs.
• Oct 30 2013: Folders for all applications are now set up with README files.
• Jan 24 2014: NASA approval for uploading the software proper.
• Jan 29 2014: All the library *.tar.gz files are now in place; applications still to do.
• Feb 05 2014: All straightforward applications have been uploaded with simple build scripts.
• Feb 10 2014: UPDATE_GRID has been added; it and GSMOOTH now use xyzq_io, not the earlier cfd_io_package.
• Jun 30 2014: Someone needed the DECONSTRUCT utility. A few updates since Feb 10 include solid angle utilities in ugridlib, a handful of functions in special_functions, and a reworked form of the HEMISPHERES_OF_SIGHT application that defines lines of sight at a point on a convex body via a triangulated quadrant of a hemisphere rather than via latitude/longitude discretization.
• Jul 03 2014: TRI_TO_TRI has been added; a triangulation_io glitch has been corrected.
• Aug 07 2014: EXTRACT_BLAYER_DATA has been added to the BLAYER folder.
• Aug 14 2014: Optimal_Interpolation now contains the package for treating unstructured data as modified at NASA Ames from Alexander Barth's original, following NASA approval of its added BSD 2-Clause License.
• Sep 05 2014: FILTER_LINES and MERGE_TABLES have been added.
• Sep 24 2014: Traj_Fit has been added. It curve-fits heat flux or pressure pulse data using f(rho(t),V(t)) = C rho(t)**m V(t)**n within the QNMDRIVER2 framework, as might be needed for TPS sizing at an entry vehicle body point from selected CFD data points.
• Oct 03 2014: The table_io module used by Traj_Fit has been updated.
• Oct 22 2014: The triangulation_io package has been extended with options for calculation of area, volume, CM, and moments of inertia. See the new TRIANGULATION_TOOL for driving these options along with shift/scale/rotate options.
• Nov 17 2014: Unstructured volume analogues of unstructured surface utilities have been added to triangulation_io and are driven by TRIANGULATION_TOOL.
• Mar 18 2015: An apparently inconsequential glitch in BLAYER has been remedied. This version can also read [unformatted] volume datasets to speed processing of large-grid cases.
• Mar 13 2015: OUTBOUND now has an option to applied a CONSTANT margin as a way of moving the forebody boundary a little while barely affecting the wake boundary.
• Apr 15 2015: The ADT rapid search package (/adt) now has 2-space multi- block curve analogues of the 3-space structured multiblock surface grid utilities. LINES_OF_SIGHT_2D uses these to deal with reflected axisymmetric 2-space volume grid. SURFACE_INTERP_2D has been added, using the same 2-space ADT utilities.
• Aug 23 2016: TET_INTERP has been added to interpolate tetrahedral volume data to a structured multiblock grid.
• Mar 17 2017: SORT_ROWS (added Feb 14) has been extended to allow more than one numeric string in a text column, and to allow output in descending order if desired. Other recent refinements: COLUMNEDIT now allows extraction of more than one column at a time; the table_io module has an updated table_io_read_alpha utility prompted by SORT_ROWS that handles the case of all lines/rows treated as text and having the same number of columns (with no header records assumed). Previously, all rows were interpreted as header records, meaning the table appeared empty.
• Jun 23 2017: NEQAIR_DATA, NEQAIR_Integration, and PREPARE_NEQAIR_DATA have been added to assist radiation calculations with NEQAIR. NEQAIR itself should be obtained through the Commercial Technology Office at NASA Ames Research Center.
• Jan 04 2018: Added A2B utility. Since June, minor changes have been made to GU, BLAYER, LINES_OF_SIGHT, SHOCK_STAND_OFF, and OUTBOUND.
• Jun 06 2018: Added Aero_Coefs application (supplement to DPLR's Postflow). Since January, updates have been made to geomlib, gridlib, progtools, searchlib, CAPSULE_GRID, CONVERTQ, GU, HEMISPHERES_- OF_SIGHT, NEQAIR_Integration, RADIAL_INTERP, and RESHAPE3D.
• Sep 19 2018: Added EXTRACT_BLOCKS_2D and EXTRACT_FUNCTIONS; xyq_io and f_io were missing from the xyzq_io folder; since June, several triangulation utilities have been extended to overcome any single-zone assumptions, NEQAIR_Integration has been improved, and POLAR_INTERP has had an option added to generate spoked body points (but see also CAPSULE_SPOKES, which had been over- looked here as well).
• Nov 07 2018: Added SLOS (structured grid form of USLOS for lines of sight).
• Mar 07 2021: Release updated CMake build system. Move repository to NASA's public GitHub. Various small improvements to radial_interp, refine, capsule_grid, and prepare_neqair_data.
• Nov 07 2021: Added BODY_POINT_DATA and miscellaneous updates to repository.
• Nov 20 2021: Re-reviewed and approved for open source release by Ames Research center under the NASA Open Source License v1.3. Added updated license file and contributor license agreements.
• May 19 2022: Added USINTERP (driver for the optimal interpolation package), USFLOWINTERP and USREFLECT for operating on Tecplottable outputs from US3D, multiple new routines in geomlib and ugridlib needed by these applications, updates to USLOS, triangulation_io and triangulation_tool, and minor updates to gsmooth, tri_to_tri, and tri_to_quad. An lapacksubset library has also been added because of changes to lib/optinterp/optimal_interpolation.f90. It is needed by the symmetric eigenvalue routines added to linsys.
• Oct 23 2022: Added DECONSTRUCT (3D structured grid/flow --> unstructured form).
• Dec 05 2022: Added WEDGE (2D structured --> 3D wedge grid & optional solution).
• Dec 30 2022: Added 1-D radial basis function interpolation (interplib & SMOOTH).