Structure and Extinction of Low Strain Rate Non-Premixed Flames by an Agent in Microgravity (NISTIR 7445)
Anthony P. Hamins, Matthew F. Bundy, C B. Oh, Stephen P. Fuss, J. Logue
This final report describes the study that has been supported through the National Aeronautics and Space Administration (NASA) microgravity grants program from February 2004 through March 2007. This work was a continuation of a NASA microgravity grant that was active from February 1999 through September 2003. The work has used computations and measurements to investigate the structure and suppression of low strain rate non-premixed flames. This final report, on the latest grant, includes a summary of the work done on the contract and a list of publications. The work during this grant period focused on both measurements and calculations and included the following: (*) Continued development of the two-dimensional simulation with finite rate chemistry. These publications are provided in Appendices 1 and 2. These calculations considered extinction of methane-air diffusion flames with N2 added to the fuel stream. The work compares calculations with our earlier measurements made in normal gravity and in microgravity using the NASA 2.2 s drop tower, (*) Two-dimensional calculations were completed .that considered the extinction of methane-air diffusion flames with CO2 added to the fuel stream in normal and microgravity. This study is provided in Appendix 3. The computations were compared to the N2 addition results, (*) Flame extinction studies on the normal gravity extinction of propane were conducted. The results of this study are provided in Appendix 4, (*) Finally, spectroscopic measurements were conducted on key flame intermediates to support detailed modeling of radiative exchange in near-extinction flames. Wakasuki et al. developed a method to estimate the temperature dependence of absorption coefficients through an extrapolation algorithm. This publication is provided in Appendix 5. Spectroscopic measurements are important to understand the mechanisms of extinction associated with flames being suppressed by agents.
, Bundy, M.
, Oh, C.
, Fuss, S.
and Logue, J.
Structure and Extinction of Low Strain Rate Non-Premixed Flames by an Agent in Microgravity (NISTIR 7445), NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.IR.7445
(Accessed November 30, 2023)