2D soot concentration and burning rate of a vertical PMMA slab using Laser-Induced Incandescence

Large eddy simulation of upward flame spread on PMMA walls with a fully coupled fluid–solid approach

“…The inclusion of the leading edge modification was found to improve the accuracy in the convective heat flux prediction near the edge of the PMMA sample. In the validation of the soot volume fraction f v of Hebert[58], the predicted peakamount and position are in reasonably agreement with the experimental data. In comparison with the large scale flame spread measurement of Liang et al [10], the model predicted the pyrolysis and flame heights (x p and x f ) with reasonably good accuracy.…”

“…The predicted peak f v is located closer to PMMA wall in comparison with the location for the peak temperature. For x wall = 0.255, the maximum f v was between 250 to 450 ppb in the five measurements of Hebert et al [58] and 207 ppb in the present prediction; for x wall = 0.355, the measured peak were between 250 and 450 ppb [58] while the predicted peak is 317 ppb.…”

“…To validate the model for the soot volume fraction f v , the wall fire of Hebert et al[58] was computed. In the experiments, the PMMA size was originally 0.45 (H) × 0.25 (W) × 0.03 (d) m but the front side of the PMMA wall was covered with a thick steel frame to avoid unnecessary flame spread.…”

A layer-peeling method for signal trapping correction in planar LII measurements of statistically steady flames

“…However, the soot particles present along the path between the probe volume (source of emission) and the detector can attenuate a portion of S LII through absorption and scattering, causing the detected LII signal (S c ) after attenuation to be lower than the actual one, leading to an underestimation of f s if the trapping effect is not corrected. The signal trapping effect represents a source of uncertainty in the determination of f s and primary particle size using LII, which can become important in large pool-fires [7], high-pressure flames [4,8] or in general, flames presenting a combination of large optical path and soot loading (large optical thickness) [15,17], especially for short-wavelength detection [18]. Some methods have been proposed to correct the signal trapping in 2D [18][19][20][21][22] axisymmetric flames by conducting additional light extinction (LE) measurements.…”

Study on the role of soot and heat fluxes in upward flame spread using a wall-resolved large eddy simulation approach

“…Some modifications were also introduced to consider laminar-turbulent transition, in-depth radiation in the PMMA slabs and regression of the PMMA surface. Validations were conducted with the pyrolysis cases of Pizzo et al [18], the fire spread measurements of Huang and Gollner [19] and Liang et al [6], as well as soot measurements of Hebert et al [20]. Because of the complexity of underlining physics, the authors reported a sensitivity study on modelling for laminar-turbulent transition for combustion, radiation, ignition, and soot formation/oxidation.…”