Two-dimensional soot distributions in buoyant turbulent fires

Abstract Spatially resolved two-dimensional soot volume fractions were measured using laser-induced incandescence in 7.1 cm methane and ethylene turbulent buoyant flames to study the distributions of soot in vertical and horizontal planes, and to provide data for soot model validation. Factors affecting the LII signals were considered including the laser energy profile and the laser attenuation effects. The absolute soot volume fractions were obtained by comparison to existing extinction measurements. The instantaneous soot images were collected to cover the entire flame height. Statistical quantities of soot volume fractions including mean, root mean square, probability density function, and spatial correlation coefficient were calculated at five downstream locations. The results show that instantaneous distributions of soot volume fractions exhibit significant differences compared to the ensemble averages, strong fluctuation around the mean, relatively homogeneous probability density function, and highly anisotropic spatial correlation.

[1]  R. L. Wal.  Laser-induced incandescence: detection issues. , 1996 .

[2]  R. Santoro,et al.  Two-dimensional imaging of soot volume fraction by the use of laser-induced incandescence. , 1995, Applied optics.

[3]  Takashi Kashiwagi,et al.  Estimate of flame radiance via a single location measurement in liquid pool fires , 1991 .

[4]  KoHse-HoingHaus.  Applied Combustion Diagnostics , 2002 .

[5]  Jay P. Gore,et al.  Heat Feedback to the Fuel Surface in Pool Fires , 1994 .

[6]  Jay P. Gore,et al.  Simultaneous emission absorption measurements in toluene-fueled pool flames: Mean and RMS Properties☆ , 1992 .

[7]  Christof Schulz,et al.  Laser-Induced Incandescence , 2006 .

[8]  Robert J. Santoro,et al.  Spatially resolved measurements of soot volume fraction using laser-induced incandescence , 1994 .

[9]  L. Melton,et al.  Soot diagnostics based on laser heating. , 1984, Applied optics.

[10]  Pierre Joulain,et al.  The behavior of pool fires: State of the art and new insights , 1998 .

[11]  C. Dasch.  Continuous-wave probe laser investigation of laser vaporization of small soot particles in a flame. , 1984, Applied optics.

[12]  C. McEnally,et al.  Flow time effects on hydrocarbon growth and soot formation in coflowing methane/air non-premixed flames , 1998 .

[13]  N Ladommatos,et al.  Optical diagnostics for soot and temperature measurement in diesel engines , 1998 .

[14]  Takashi Kashiwagi,et al.  Radiative heat feedback in a toluene pool fire , 1992 .

[15]  H. Bockhorn,et al.  Two-dimensional imaging of soot volume fractions, particle number densities and particle radii in laminar and turbulent diffusion flames , 1998 .

[16]  Glenn P. Forney,et al.  Fire Dynamics Simulator: Technical Reference Guide (NISTIR 6467) , 2000 .

[17]  Michael A. Delichatsios,et al.  Air entrainment into buoyant jet flames and pool fires , 1987 .

[18]  Jay P. Gore,et al.  Temperature and soot volume fraction statistics in toluene-fired pool fires , 1993 .

[19]  C. Shaddix,et al.  Laser-induced incandescence measurements of soot production in steady and flickering methane, propane, and ethylene diffusion flames , 1996 .

[20]  Alan C. Eckbreth,et al.  Effects of laser-modulated particulate incandescence on Raman scattering diagnostics , 1977 .

[21]  Jay P. Gore,et al.  Structure and spectral radiation properties of turbulent ethylene/ air diffusion flames , 1988 .