Numerical investigation of pressure dependence of yield sooting tendencies

The sooting tendencies of various fuels have been historically quantified via the Threshold Sooting Index (TSI), which is based on spoke point measurement. More recently, a Yieldbased Sooting Index (YSI) has been proposed with lower measurement uncertainties, high throughput, and applicability to low-volatility fuels. YSI is experimentally measured in an atmospheric-pressure, laminar, non-premixed co-flow methane/air flame generated with a Yale Co-flow Burner. As such, YSI quantifies soot propensity under ambient pressure, which is much lower than the pressure levels in practical devices. In this work, we numerically investigate the pressure dependence of YSI for a wide range of fuels. We first validate our numerical models in a series of high pressure laminar co-flow non-premixed flames with pressures ranging from 5atm to 20atm. We then use these numerical models to predict the YSI of a wide range of fuels under pressures from 1atm to 20atm. Finally, the predicted YSI values under these pressure levels are compared against the experimental measurements of YSI under 1atm to quantify the pressure dependence of YSI.