Simultaneous instantaneous measurements of soot volume fraction, primary particle diameter, and aggregate size in turbulent buoyant diffusion flames

Application of an Optical Diagnostic (LII/ELS) to Measure Soot Formation Trends within Turbulent Buoyant Non-Premixed Flames

“…Similar to the trends observed above, after 90 cm the air entrainment results in soot oxidation in the flame and soot is observed less often (Lee et al 2009). Crosland et al (2015) also observed that the reduction in fv towards the tip of the flame is due to an increase in intermittency. Since the trends for the time-averaged fv and the intermittency are similar, it is important to plot the SVF without including the effects of intermittency to determine if the differences in the time-averaged fv curves for the TWG and TWOG cases are due to increased intermittency.…”

“…They all generally conclude that the turbulence levels in the flow have an inverse relation to soot formation, but the impact of exit Reynolds number on soot yield for a given fuel mixture is weaker compared to the impact of higher heating value (HHV) (via a change in fuel mixture) on soot formation. This relationship between the turbulence in the flow field and its impact on soot formation has only been studied for buoyancy-driven non-premixed turbulent flames by Crosland et al (2015). They varied the burner exit nozzle and fuel flow rates and showed that there are non-linear relationships between residence time and soot concentration in turbulent buoyant non-premixed flames.…”

“…In continuation of the work of Crosland et al (2015), Sawires (2017) employed the same combination of diagnostics but scaled up the set-up to allow it to be used with largescale turbulent flames. This update was successfully tested with a non-premixed laminar flame burning ethylene on a well-characterized co-flow burner previously described in Snelling et al (2004).…”

“…Intermittency is expressed as 1-Ω, where Ω is the intermittency index, defined as the ratio of the number of measurements where soot is present Ns, i.e. instances when scatter and laser-induced incandescence signals were observed, to the total number of measurements N (Ω = Ns/N) (Crosland et al 2015). Figure 5.2 plots the axial profile of the mean intermittency of the flames with (TWG) and without the turbulence grid (TWOG) installed.…”

Methodology and Experiments to Determine Soot and NOx Yields from a Vertical Lab-Scale Flare Burning Alkane-Mixtures and Ethylene

“…The lack of quantitative data with defined uncertainties in the range of operating conditions examined in the current work is important for qualifying the effects of operating regimes on the emissions of turbulent non-premixed diffusion flames. The critical lack of data available in literature to allow for accurate quantification of soot emissions from buoyancy-dominated flames is a compelling reason for the continuation of research on the subject (Crosland et al, 2014).…”