Gpyro - Generalized Pyrolysis Model for Combustible Solids

Gpyro is an open source computer model that describes the thermal response of solid materials exposed to radiative or convective heating, including thermo-oxidative pyrolysis of the condensed phase.

Gpyro can be used for 0D, 1D, 2D, and 3D simulations and can write NIST Smokeview files for visualization of 2D and 3D simulations. Gpyro contains the physics necessary to simulate pyrolysis of thermoplastic and charring solids, intumescent coatings, and smolder in porous media. It can be applied as a boundary condition in a modified version of FDS6 (disclaimer: Gpyro and its linking to FDS is in no way supported by or developed by NIST or the FDS developers). Coupled to Gpyro is a material property estimation program that can be used to help estimate the required material properties from experimental data (Cone Calorimeter or similar, thermogravimetric analysis, and differential scanning calorimetry). At the present time, brute force search, genetic algorithm optimization, genetic algorithm/simulated annealing, stochastic hillclimber, and shuffled complex evolution optimization methods are available.


The Gpyro software consists of three separate executable files (standalone, property estimation, and FDS/Gpyro) so it isn't really necessary to "install" Gpyro. The easiest way to get started is to download a .zip file containing the Gpyro repository and executables. Gpyro Version 0.8186 (current as of January 29, 2018) can be downloaded at This archive includes Windows executables but it does not include linux executables because it's difficult to build portable linux executables due to library incompatabilites across linux distributions and versions. The property estimation and coupled FDS/Gpryo Windows executables are currently compiled against MS-MPI v8 ( To run the property estimation or FDS/Gpyro programs in Windows you will have to install MS-MPI. To visualize 2D and 3D simulations, you will also need to install NIST Smokeview, which can be downloaded from

Building from source

If you plan to run Gpyro under linux or would like to work with the most recent source code, executing a shell script such as the following should do the trick:


rm -f -r gpyro
svn checkout svn://
cd ./gpyro/build/linux/
sh # or sh

Depending on the configuration of your system or available compilers, you may have to modify the make scripts (, and/or the Makefiles. We use OpenMPI 3.0.0 ( but it is possible to build with other MPI installations. The make scripts use several environment variables to specify compiler paths and the directory to which the built binaries will be copied, so you may wish to add lines similar to these to your ~/.bashrc file:

export GPYRO_FCOMPL_MPI_INTEL=/usr/local/openmpi-3.0.0_intel/bin/mpifort
export GPYRO_FCOMPL_MPI_GNU=/usr/local/openmpi-3.0.0_gnu/bin/mpifort
export GPYRO_BINARY_DIRECTORY=/usr/local/bin


Gpyro’s user guide and technical reference are available here:

These documents are somewhat out of sync with the current code in the repository. The developer is in the process of preparing updated documentation, but Gpyro is an unfunded project that is developed as necessary for internal project work or at at the request of users. The user may find some of the publications in the References section below useful.

Sample calculations

A logical place to get started is the sample calculations included in the source repository. These can be found in the "samples" folder. In windows, you can run the samples by executing run_samples.bat, and under linux by executing the samples Like the build scripts, the script uses several environment variables so if the default values are not appropriate for your system you will have to put some lines such as this in your ~/.bashrc file:

export GPYRO_BINARY_DIRECTORY=/usr/local/bin
export GPYRO_MPIRUN=/usr/local/openmpi-3.0.0_gnu/bin/mpirun
export GPYRO_COMPILER=gnu # Set to 'gnu' or 'intel'
export GPYRO_DEBUG=no # Set to 'yes' or 'no'

General questions, bug reports, and feature/enhancement requests

To ask a question, report a problem/bug, or request a feature enhancement, please use the ticket system built into Trac. Due to spambots posting thousands of bogus tickets, anonymous account registration has been disabled. But if you send email to lautenberger@… with a username and password, an account will be created manually. After logging in, click on "New Ticket" and provide as much information about your question, problem, or feature request as possible. Attach input files if appropriate. To allow for better ticket tracking, if you are reporting multiple issues please submit one issue per ticket.

Sponsorship and disclaimer

Gpyro was originally developed at UC Berkeley under NASA sponsorship as part of the Forced Ignition and Spread Test (FIST) project and a Graduate Student Researcher Program (GSRP) extension to FIST and later under NSF Award 0730556, "Tackling CFD Modeling of Flame Spread on Practical Solid Combustibles". Some of the theory, applications, verification, and validation of Gpyro, its predecessors, the material property estimation algorithm, and linking to FDS is scattered over several publications listed in the References section below.

This material is based upon work supported by the National Science Foundation under Grant No. 0730556. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation (NSF).

Note on commercial use

Gpyro is open source, public domain software. It may be used by anyone for any purpose subject to the Open Source Initiative/MIT License.


  1. Lautenberger, C., Zhou, Y.Y. and Fernandez-Pello, A.C., "Numerical Modeling of Convective Effects on Piloted Ignition of Composite Materials," Combustion Science and Technology 177 1231-1252 (2005).
  1. Lautenberger, C., Rein, G. and Fernandez-Pello, A.C., "The Application of a Genetic Algorithm to Estimate Material Properties for Fire Modeling from Bench-Scale Fire Test Data," Fire Safety Journal 41 204-214 (2006).
  1. Rein, G., Lautenberger, C., Fernandez-Pello, A.C., Torero, J.L. and Urban, D.L., "Application of Genetic Algorithms and Thermogravimetry to Determine the Kinetics of Polyurethane Foam in Smoldering Combustion," Combustion and Flame 146 95-108 (2006).
  1. Lautenberger, C., McAllister, S., Rich, D., and Fernandez-Pello, C., "Modeling the Effect of Environmental Variables on Opposed-Flow Flame Spread Rates with FDS," International Congress on Fire Safety in Tall Buildings, Santander, Spain, October 2006.
  1. Lautenberger, C., McAllister, S, Rich, D., and Fernandez-Pello, C., "Effect of Environmental Variables on Flame Spread Rates in Microgravity," 45th AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, January 2007, AIAA Paper 2007-383.
  1. Lautenberger, C. and Fernandez-Pello, C., "A Generalized Pyrolysis Model for Combustible Solids," Fifth International Seminar on Fire and Explosion Hazards, Edinburgh, UK, April 2007.
  1. Lautenberger, C., "A Generalized Pyrolysis Model for Combustible Solids," Ph.D Dissertation, Department of Mechanical Engineering, University of California, Berkeley, Fall 2007.
  1. Lautenberger, C. & Fernandez-Pello, A.C., "Modeling Ignition of Combustible Fuel Beds by Embers and Heated Particles," Forest Fires 2008 (2008).
  1. Lautenberger, C., Kim, E., Dembsey, N. & Fernandez-Pello, C., "The Role of Decomposition Kinetics in Pyrolysis Modeling – Application to a Fire Retardant Polyester Composite," Fire Safety Science 9: 1201-1212 (2008).
  1. Lautenberger, C. & Fernandez-Pello, A.C., "Generalized Pyrolysis Model for Combustible Solids," Fire Safety Journal 44 819-839 (2009).
  1. Lautenberger, C. & Fernandez-Pello, A.C., “A Model for the Oxidative Pyrolysis of Wood,” Combustion and Flame 156 1503-1513 (2009).
  1. Dodd, A.B., Lautenberger, C., and Fernandez-Pello, A.C., "Numerical Examination of Two-Dimensional Smolder Structure in Polyurethane Foam," Proceedings of the Combustion Institute 32: 2497-2504 (2009).
  1. Lautenberger, C. & Fernandez-Pello, C., "Optimization Algorithms for Material Pyrolysis Property Estimation," Fire Safety Science 10 751-764 (2011).
  1. Dodd, A.B., Lautenberger, C., & Fernandez-Pello, A.C., "Computational Modeling of Smolder Combustion and Spontaneous Transition to Flaming," Combustion and Flame 159 448–461 (2012).
  1. Lautenberger, C., "Gpyro3D: A Three Dimensional Generalized Pyrolysis Model," Fire Safety Science 11 193-207 (2014).
Last modified 3 months ago Last modified on 12/08/18 10:54:30