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

Overview

March 30, 2009: Gpyro 0.704 is available by SVN checkout. Includes material property estimation by hybrid genetic algorithm/simulated annealing optimization. Also includes modifications to FDS/Gpyro coupling related to laminar flame spread. Testing is underway and documentation to be updated soon.

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. It is being developed at UC Berkeley under NSF sponsorship as part of a larger project to improve capabilities for CFD-based modeling of fire growth on practical solid combustibles.

Gpyro can be used for 0D, 1D, and 2D simulations and can write NIST Smokeview files for visualization of 2D 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 FDS (disclaimer: Gpyro and its linking to FDS is in no way supported by or developed by NIST or VTT; the coupled Gpyro/FDS code is being used as part of an active research project). Part of 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 and genetic algorithm optmization are available, but other optimization methods are being investigated.

Gpyro is a research code under active development, check this page frequently for updates! A draft Users' Guide and Technical Reference have been prepared and can be downloaded from links to the above right. Please refer to these documents for technical details of Gpyro and instructions for installation and running simulations.

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. It is now being developed under NSF Award 0730556, "Tackling CFD Modeling of Flame Spread on Practical Solid Combustibles". Some of the theory, applications, 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.

Downloads

Above and to the right are links to several featured downloads:

• gpyro_0.700.zip - Gpyro 0.700 source code, samples, compiled executables, Makefiles, etc.
• gpyro_technical_reference.pdf - Gpyro 0.700 Technical Reference
• gpyro_users_guide.pdf - Gpyro 0.700 Users Guide

These downloads are updated only every few weeks to every few months; the most recent project files can be obtained by Subversion checkout. In general, you should always try to work with a recent version of Gpyro.

A full list of downloads can be found on the Downloads page. Note that some files are deprecated but can still be downloaded.

References

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).

2. 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).

3. 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).

4. 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.

5. 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.

6. 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.

7. Lautenberger, C., "A Generalized Pyrolysis Model for Combustible Solids," Ph.D Dissertation, Department of Mechanical Engineering, University of California, Berkeley, Fall 2007. http://repositories.cdlib.org/cpl/fs/LautenbergerPhD/

8. Lautenberger, C. & Fernandez-Pello, A.C., "Generalized Pyrolysis Model for Combustible Solids," accepted for publication in Fire Safety Journal. http://me.berkeley.edu/cpl/publications/2009-03-17_FSJ_GenPyro.pdf

9. Lautenberger, C. and Fernandez-Pello, A.C., A Model for the Oxidative Pyrolysis of Wood, accepted for publication Combustion and Flame. http://me.berkeley.edu/cpl/publications/2009-04-08_CNF_oxidative_pyrolysis.pdf

10. 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).

11. 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). http://me.berkeley.edu/cpl/publications/9th_iafss_paper_149.pdf

12. Lautenberger, C. & Fernandez-Pello, A.C., "Modeling Ignition of Combustible Fuel Beds by Embers and Heated Particles," Forest Fires 2008 (2008). http://me.berkeley.edu/cpl/publications/lautenberger_forest_fires_2008.pdf

Note on commercial use

Gpyro is open source, public domain software. It may be used commercially by anyone subject to the Open Source Initiative/MIT License. Specifically note the following paragraph from the Open Source Initiative/MIT License:

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

All requests for fire expert consulting services related to application of Gpyro are now handled through Reax Engineering.