Advertisement

Fire Technology

, Volume 56, Issue 1, pp 5–32 | Cite as

Flame Growth Around a Spherical Solid Fuel in Low Speed Forced Flow in Microgravity

  • Makoto EndoEmail author
  • James S. T’ien
  • Paul V. Ferkul
  • Sandra L. Olson
  • Michael C. Johnston
Article

Abstract

To further our understanding of flammability and quenching limit of thick solid fuels, a microgravity experiment Growth and Extinction Limits is to be conducted aboard the International Space Station with the emphasis to quantify the effect of the flame heat loss to the thermally thick solid interior by directly measuring the sub-surface temperature gradient. A precursor microgravity combustion experiment in the Burning and Suppression of Solids (BASS) project was used to assess the experimental operation and validate the accompanied numerical model. The present paper reports the development of the flame model over a solid sphere in low-speed pure convective flow (less than 100 cm/s). Computed time sequence result of one of the BASS conditions is presented. The combination of gas phase reaction rate, solid internal temperature and surface heat flux distribution reveals the effect of solid in-depth heat-up on flame growth. The experimental observations agree with the trend predicted by the model. For thick solids, flame quenching limit in low speed flow is not only a function of flow speed but also the degree of solid interior heat-up. Flammability limit can have profound implication to the current spacecraft fire protection protocol that requires turning-off of circulation flow in case of detected fire. The present and the follow-up studies will provide more quantitative estimate of the low velocity-quenching limit with heated samples. For the Polymethylmethacrylate spheres investigated, the limit is lower than 2 cm/s in air.

Keywords

Thermally-thick Flammability Quenching Flame growth GEL SoFIE BASS Solid fuel 

Acronyms

BASS

Burning and Suppression of Solids (project)

CIR

Combustion Integrated Rack

DARTFire

Diffusive and Radiative Transport in Fires (project)

GEL

Growth and Extinction Limit (project)

ISS

International Space Station

PMMA

Poly(methyl methacrylate)

SoFIE

Solid Fuel Ignition and Extinction (project)

SSCE

Solid Surface Combustion Experiments (project)

Nondimensional Properties

\(\bar{\varvec{\tau }}\)

\(L {\varvec{\tau }}/(u_\infty \mu _\infty )\)

\(\bar{\dot{Q}}_R\)

\({\dot{Q}}_R L /\lambda _s T_\infty\)

\(\overline{{\dot{m}}}\)

\({\dot{m}}/(\rho _\infty u_\infty )\)

\(\tau\)

Step size for gas phase calculation, CFL number times \(t /(L/u_\infty )\)

Bo

Boltzmann number\(, \rho _\infty u_\infty C_{p\infty }/(\sigma T_\infty ^3)\)

Le

Lewis number\(, \alpha _\infty /D_\infty\)

Pr

Prandtl number\(, \mu _\infty /(\alpha _\infty \rho _\infty )\)

Re

Reynolds number\(, \rho _\infty u_\infty L/\mu _\infty\)

\({{\bar{\lambda }}}\)

\(\lambda / \lambda _\infty\)

\({{\bar{\mu }}}\)

\(\mu /\mu _\infty\)

\({{\bar{\omega }} }\)

\(\omega /(\rho _\infty u_\infty /L)\)

\({{\bar{D}}_i}\)

\(D_i / D_\infty\)

\({{\bar{H}}_{oc}}\)

\(H_{oc}/(C_{p\infty }T_\infty )\)

\({{\bar{L}}_q}\)

\(L_q \rho _\infty u_\infty L/ (\lambda _{s^*} T_\infty )\)

\({{\bar{p}}}\)

\((p-p_\infty )/(\rho _\infty u_\infty ^2)\)

\({{\bar{Q}}_{in} }\)

\(Q_{in}/( u_\infty \rho _\infty C_{p\infty } T_\infty /L )\)

\({{\bar{Q}}_{R} }\)

\(Q_R/(\sigma T_\infty ^4/L)=-\nabla \cdot {\mathbf{q_{r}}}/(\sigma T_\infty ^4/L)\)

\({{\bar{T}}}\)

\(T/T_\infty\)

\({{\bar{t}}}\)

\(t/(L^2/\alpha )\)

\({\bar{\mathbf{u}} }\)

\({\mathbf{u}}/{u_\infty }\)

Dimensional Properties

\(\alpha\)

Thermal diffusivity

\(\kappa\)

Absorption coefficient

\(\lambda\)

Thermal conductivity

\(\mu\)

Viscosity

\(\omega\)

Gas phase reaction rate

\(\omega _{mol}\)

Fuel vapor consumption rate in mole/(volume\(\cdot\)time)

\(\rho\)

Density

\(\sigma\)

Stefan–Boltzmann constant

a

Stretch rate at the stagnation point, \(1.5u_\infty /R\)

\(B_g\)

Pre-exponential factor for gas phase reaction

\(B_s\)

Pre-exponential factor for solid fuel decomposition

\(C_p\)

Specific heat

D

Mass diffusivity

\(E_g\)

Activation energy of gas phase reaction

\(E_s\)

Activation energy for solid fuel decomposition

G

Incident radiation

\(H_{oc}\)

Heat of combustion of fuel

I

Radiative intensity

L

Reference length, \(\sqrt{\alpha _\infty /a}\)

\(L_q\)

Latent heat of vaporization

p

Pressure

\(Q_{in}\)

External heat input (i.e. igniter)

R

Radius of curvature at stagnation point

T

Temperature

Y

Species mass fraction

\(\mathbf{u}\)

Velocity vector

\({\varvec{\tau}}\)

Viscous stress tensor

\({\dot{m}}\)

Burning rate of solid fuel

t

Time

Subscript

\(\infty\)

Reference state property. Value at the inlet except for pressure and density, former is defined at the outlet. \(\rho _\infty\) is computed by \(p_\infty\) and \(T_\infty\) using the ideal gas law

\(\nu\)

At a given wave number

b

Black body value

i

For chemical specie i

s

Solid phase property

\(s^*\)

Representative value of the solid fuel material

Notes

Acknowledgements

This research is supported by the National Aeronautics and Space Administration (NASA). Authors would like to thank the astronauts Don Pettit, Joe Acaba, and Suni Williams for conducting the BASS experiments. This work made use of the High Performance Computing Resource in the Core Facility for Advanced Research Computing at Case Western Reserve University and the Ohio Supercomputer Center.

References

  1. 1.
    Altenkirch RA, Tang L, Sacksteder K, Bhattacharjee S, Delichatsios MA (1998) Inherently unsteady flame spread to extinctionover thick fuels in microgravity. Symp (Int) Combust 27(2):2515–2524CrossRefGoogle Scholar
  2. 2.
    Buckmaster J (1996) Edge-flames and their stability. Combust Sci Technol 115(1–3):41–68CrossRefGoogle Scholar
  3. 3.
    Cheatham S, Matalon M (2000) A general asymptotic theory of diffusion flames with application to cellular instability. J Fluid Mech 414:105–144MathSciNetCrossRefGoogle Scholar
  4. 4.
    Chen RH, Mitchell GB, Ronney PD (1992) Diffusive-thermal instability and flame extinction in nonpremixed combustion. Symp (Int) Combust 24(1):213–221CrossRefGoogle Scholar
  5. 5.
    Delichatsios MA, Altenkirch RA, Bundy MF, Bhattacharjee STang L, Sacksteder K (2000) Creeping flame spread along fuel cylinders in forced and natural flows and microgravity. Proc Combust Inst 28(2):2835–2842CrossRefGoogle Scholar
  6. 6.
    Endo M (2016) Numerical modeling of flame spread over spherical solid fuel under low speed flow in microgravity: model development and comparison to space flight experiments. Ph.D. thesis, Case Western Reserve University, Case Western Reserve UniversityGoogle Scholar
  7. 7.
    Fujita O (2015) Solid combustion research in microgravity as a basis of fire safety in space. Proc Combust Inst 35(3):2487–2502CrossRefGoogle Scholar
  8. 8.
    Goldmeer JS, T’ien JS, Urban DL (1999) Combustion and extinction of PMMA cylinders during depressurization in low-gravity. Fire Saf J 32:61–88CrossRefGoogle Scholar
  9. 9.
    Ivanov AV, Balashov YV, Andreeva TV, Melikhov AS (1999) Experimental Verification of Material Flammability in Space. NASA/CR-1999-209405, E-11932, NAS 1.26:209405Google Scholar
  10. 10.
    Johnston MC, Hsu SY, Olson SL, T’ien JS, Ferkul PV (2018) Flame dynamics of preheated thermally thick solid fuel during a drop transition from normal gravity. In: 34th ASGSR meeting. BethesdaGoogle Scholar
  11. 11.
    Kimzey JH (1974) Skylab experiment M 479 zero gravity flammability. In: Proceedings of the 3rd space processing symposium on skylabGoogle Scholar
  12. 12.
    Olson S, T’ien J (1999) Near-surface vapour bubble layers in buoyant low stretch burning of polymethylmethacrylate. Fire Mater 23:227–237CrossRefGoogle Scholar
  13. 13.
    Olson SL, Ferkul PV (2017) Microgravity flammability boundary for PMMA rods in axial stagnation flow: experimental results and energy balance analyses. Combust Flame 180: 217–229CrossRefGoogle Scholar
  14. 14.
    Olson SL, Johnston MC, Hsu SY, T’ien JS, Ferkul PV (2011) Experiments and modeling of normal gravity ignition and transition to microgravity for a PMMA sphere in a forced convective flow. In: 7th US National Meeting of the Combustion InstituteGoogle Scholar
  15. 15.
    Olson SL, T’ien JS (2000) Buoyant low-stretch diffusion flames beneath cylindrical PMMA samples. Combust Flame 121(3):439–452CrossRefGoogle Scholar
  16. 16.
    Ross H (2001) Microgravity combustion: fire in free fall. Academic Press, San DiegoGoogle Scholar
  17. 17.
    Ruff GA, Urban DL, Pedley MD, Johnson PT (2009) Fire safety. In: Musgrave GE, Larsen ASM, Sgobba T (eds) Safety design for space systems. Butterworth-Heinemann, Burlington, pp 829–883CrossRefGoogle Scholar
  18. 18.
    Seshadri K, Williams FA (1978) Structure and extinction of counterflow diffusion flames above condensed fuels: comparison between poly(methyl methacrylate) and its liquid monomer, both burning in nitrogenair mixtures. J Polym Sci Polym Chem Ed 16:1755–1778CrossRefGoogle Scholar
  19. 19.
    Soufiani A, Taine J (1997) High temperature gas radiative property parameters of statistical narrow-band model for H2O, CO2 and CO, and correlated-K model for H2O and CO2. Int J Heat Mass Transf 40(4):987–991CrossRefGoogle Scholar
  20. 20.
    Steinhaus T (1999) Evaluation of the thermophysical properties of poly (methylmethacrylate): a reference material for the development of a flammability test for micro-gravity environments. Master’s thesis, University of Maryland at College ParkGoogle Scholar
  21. 21.
    T’ien JS (1986) Diffusion flame extinction at small stretch rates: the mechanism of radiative loss. Combust Flame 65:31–34CrossRefGoogle Scholar
  22. 22.
    T’ien JS (2000) Role of radiation on microgravity flames. In: Spacebound conference. VancouverGoogle Scholar
  23. 23.
    Urban DL, Ferkul PV, Olson SL, Ruff GA, Easton J, T’ien JS, Liao YTT, Li C, Fernandez-Pello AC, Torero JL, Legros G, Eigenbrod C, Smirnov N, Fujita O, Rouvreau S, Toth B, Jomaas G (2019) Flame spread: effect of microgravity and scale. Combust Flame 199:168–192CrossRefGoogle Scholar
  24. 24.
    West J, Tang L, Altenkirch RA, Bhattacharjee S, Sacksteder K, Delichatsions MA (1996) Quiescent flame spread over thick fuels in microgravity. Symp (Int) Combust 26(1):1335–1343CrossRefGoogle Scholar
  25. 25.
    Yang CT, T’ien JS (1998) Numerical simulation of combustion and extinction of a solid cylinder in low-speed cross flow. J Heat Transf 120(4):1055–1063CrossRefGoogle Scholar
  26. 26.
    Yang JC, Hamins A, Donnelly MK (2000) Reduced gravity combustion of thermoplastic spheres. Combust Flame 120(1–2):61–74CrossRefGoogle Scholar

Copyright information

© This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply 2019

Authors and Affiliations

  1. 1.Case Western Reserve UniversityClevelandUSA
  2. 2.Universities Space Research AssociationClevelandUSA
  3. 3.NASA Glenn Research CenterClevelandUSA

Personalised recommendations