Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Measurements and Modeling of Spherical CH2F2-Air Flames



Michael J. Hegetschweiler, John L. Pagliaro, Lukas Berger, Raik Hesse, Joachim Beeckmann, Heinz Pitsch, Gregory T. Linteris


The burning velocity of mixtures of the refrigerant R-32 (CH2F2) with air over a range of equivalence ratios are studied via spherically expanding flames SEFs in a large, optically accessible spherical chamber at constant pressure. Shadowgraph images from a high-speed video camera are analysed to yield flame radius as a function of time. Data reduction techniques are explored and direct numerical simulations of the flame are performed with the FlameMaster code, using detailed kinetics. The flame radius as a function of time is accurately predicted by the simulations. Flame stretch and thermal radiation (using an optically thin model) occur simultaneously and make extraction of the unstretched burning velocity from the experimental data difficult. For these low burning velocity flames, the numerical simulations show that stretch and radiation effects are particularly important, and different data reduction schemes can have large effects on the inferred burning velocity.
Technical Note (NIST TN) - 2100
Report Number


Laminar Flame Speed, Burning Velocity, Refrigerant Flammability, R-32, Radiation, Flame stretch


Hegetschweiler, M. , Pagliaro, J. , Berger, L. , Hesse, R. , Beeckmann, J. , Pitsch, H. and Linteris, G. (2020), Measurements and Modeling of Spherical CH2F2-Air Flames, Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed May 23, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created July 26, 2020, Updated July 27, 2020