Microgravity Science and Technology

, Volume 30, Issue 4, pp 339–351 | Cite as

Cool-Flame Burning and Oscillations of Envelope Diffusion Flames in Microgravity

  • Fumiaki TakahashiEmail author
  • Viswanath R. Katta
  • Michael C. Hicks
Original Article
Part of the following topical collections:
  1. Topical Collection on Asian Microgravity Research in Physics, Materials and Life Science


The two-stage combustion, local extinction, and flame-edge oscillations have been observed in single-droplet combustion tests conducted on the International Space Station. To understand such dynamic behavior of initially enveloped diffusion flames in microgravity, two-dimensional (axisymmetric) computation is performed for a gaseous n-heptane flame using a time-dependent code with a detailed reaction mechanism (127 species and 1130 reactions), diffusive transport, and a simple radiation model (for CO2, H2O, CO, CH4, and soot). The calculated combustion characteristics vary profoundly with a slight movement of air surrounding a fuel source. In a near-quiescent environment (≤ 2 mm/s), with a sufficiently large fuel injection velocity (1 cm/s), extinction of a growing spherical diffusion flame due to radiative heat losses is predicted at the flame temperature at ≈ 1200 K. The radiative extinction is typically followed by a transition to the “cool flame” burning regime (due to the negative temperature coefficient in the low-temperature chemistry) with a reaction zone (at ≈ 700 K) in close proximity to the fuel source. By contrast, if there is a slight relative velocity (≈ 3 mm/s) between the fuel source and the air, a local extinction of the envelope diffusion flame is predicted downstream at ≈ 1200 K, followed by periodic flame-edge oscillations. At higher relative velocities (4 to 10 mm/s), the locally extinguished flame becomes steady state. The present 2D computational approach can help in understanding further the non-premixed “cool flame” structure and flame-flow interactions in microgravity environments.


Local extinction Pulsating diffusion flame Microgravity droplet combustion Negative temperature coefficient Cool flame 



This work was supported by the NASA Space Life and Physical Sciences Research and Applications Division (SLPSRA). Initial versions of this paper were presented at the 9th U. S. National Combustion Meeting, Cincinnati, Ohio, May17-20, 2015, and the 11th Asian Microgravity Symposium, Sapporo, Japan, October 25–29, 2016. The authors would like to thank Daniel Dietrich, Vedha Nayagam, and Forman Williams for their fruitful discussions and Tanvir Farouk and Frederick Dryer for providing us with the reduced n-heptane reaction mechanism.


  1. Anon.: Radiation models, International Workshop on Measurement and Computation of Turbulent Nonpremixed Flames. Accessed: 4 June 2017 (2003)
  2. Berta, P., Aggarwal, S.K., Puri, I.K.: An experimental and numerical investigation of n-heptane/air counterflow partially premixed flames and emission of NOx and PAH species. Combust. Flame 145, 740–764 (2006)CrossRefGoogle Scholar
  3. Choi, M.Y., Dryer, F.L.: Microgravity droplet combustion. In: Ross H. D. (ed.) Microgravity Combustion: Fire in Free Fall, pp 183–297. Academic Press, San Diego (2001)Google Scholar
  4. Cuoci, A., Frassoldati, T., Faravelli, E.: Ranzi: Cool flames in droplet combustion. In: XXXVI Meeting of the Italian Section of the Combustion Institute (2013)Google Scholar
  5. Cuoci, A., Frassoldati, A., Faravelli, T., Ranzi, E.: Numerical modeling of auto-ignition of isolated fuel droplets in microgravity. Proc. Combust. Inst. 35(2), 1621–1627 (2015)CrossRefGoogle Scholar
  6. Curran, H.J., Gaffuri, P., Pitz, W.J., Westbrook, C.K.: A comprehensive modeling study of n-heptane oxidation. Combust. Flame 114, 149–177 (1998)CrossRefGoogle Scholar
  7. Dietrich, D.L., Ross, H.D., Shu, Y., Chang, P., T’ie, J.S.: Candle flames in nonbuoyant atmospheres. Combust. Sci. Technol. 156, 1–24 (2000)CrossRefGoogle Scholar
  8. Dietrich, D.L., Nayagam, V., Hicks, M.C., Ferkul, P.V., Dryer, F.L., Farouk, T.I., Shaw, B.D., Suh, H.K., Choi, M.Y., Liu, Y.C., Avedisian, C.T., Williams, F.A.: Droplet combustion experiments aboard the International Space Station. Microgravity Sci. Technol. 26(2), 65–76 (2014)CrossRefGoogle Scholar
  9. Farouk, T.I., Dryer, F.L.: Isolated n-heptane droplet combustion in microgravity: “Cool Flames”—two-stage combustion. Combust. Flame 161, 565–581 (2014)CrossRefGoogle Scholar
  10. Farouk, T.I., Hicks, M.C., Dryer, F.L.: Multistage oscillatory “Cool Flame” behavior for isolated alkane droplet combustion in elevated pressure microgravity condition. Proc. Combust. Inst. 35, 1701–1708 (2015)CrossRefGoogle Scholar
  11. Hegde, U., Bahadori, M.Y., Stocker, D.P.: Temporal instability and extinction of a microgravity jet diffusion flame. AIAA paper 99-0582. In: 37th AIAA Aerospace Sciences Meeting and Exhibit (1999)Google Scholar
  12. Katta, V.R., Goss, L.P., Roquemore, W.M.: Numerical investigations of transitional H2/N2 jet diffusion flames. AIAA J. 32, 84 (1994)CrossRefGoogle Scholar
  13. Katta, V.R., Aggarwal, S.K., Roquemore, W.M.: Evaluation of chemical-kinetics models for n-heptane combustion using a multidimensional CFD code. Fuel 93, 339–350 (2012)CrossRefGoogle Scholar
  14. Leung, K.M., Lindstedt, R.P., Jones, W.P.: A simplified reaction mechanism for soot formation in nonpremixed flames. Combust. Flame 87, 289–305 (1991)CrossRefGoogle Scholar
  15. Lindstedt, R.P.: Simplified soot nucleation and surface growth steps for non-premixed flames. In: Bockhorn, H (ed.) Soot Formation in Combustion: Mechanisms and Models, pp 417–439. Springer, Heidelberg (1994)Google Scholar
  16. Liu, Y.C., Xu, Y., Hicks, M.C., Avedisian, C.T.: Comprehensive study of initial diameter effects and other observations on convection-free droplet combustion in the standard atmosphere for n-heptane, n-octane, and n-decane. Combust. Flame 171, 27–41 (2016)CrossRefGoogle Scholar
  17. Nayagam, V., Dietrich, D.L., Ferkul, P.V., Hicks, M.C., Williams, F.A.: Can cool flames support quasi-steady alkane droplet burning? Combust. Flame 159, 3583–3588 (2012)CrossRefGoogle Scholar
  18. Paczko, G., Peters, N., Seshadri, K., Williams, F.A.: The role of cool-flame chemistry in quasi-steady combustion and extinction of n-heptane droplets. Combust. Theor. Model. 18, 4–5 (2014)CrossRefGoogle Scholar
  19. Phillips, H.: Flame in buoyant methane layer. Proc. Combust. Inst. 10, 1277–1283 (1965)CrossRefGoogle Scholar
  20. Roquemore, W.M., Katta, V.R.: Role of flow visualization in the development of UNICORN. J. Visual. 2, 257–272 (2000)CrossRefGoogle Scholar
  21. Takahashi, F., Katta, V.R.: Unsteady extinction mechanisms of diffusion flames. Proc. Combust. Inst. 26, 1151–1160 (1996)CrossRefGoogle Scholar
  22. Takahashi, F., Katta, V.R.: Structure of propagating edge diffusion flames in hydrocarbon fuel jets. Proc. Combust. Inst. 30, 375–382 (2005)CrossRefGoogle Scholar
  23. Takahashi, F., Linteris, G.T., Katta, V.R.: Vortex-coupled oscillations of edge diffusion flames in coflowing air with dilution. Proc. Combust. Inst. 31, 1575–1582 (2007)CrossRefGoogle Scholar
  24. Williams, F.A.: Combustion Theory, vol. 52. Benjamin/Cummings Publishing, Menlo Park (1985)Google Scholar
  25. Won, S.H, Kim, J., Shin, M.K., Chung, S.H., Fujita, O., Mori, T., Choi, J.H., Ito, K.: Normal and microgravity experiment of oscillating lifted flames in coflow. Proc. Combust. Inst. 29, 37–44 (2002)CrossRefGoogle Scholar

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© Springer Science+Business Media B.V., part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of Mechanical and Aerospace EngineeringCase Western Reserve UniversityClevelandUSA
  2. 2.Innovative Scientific Solutions, Inc.DaytonUSA
  3. 3.NASA Glenn Research CenterClevelandUSA

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