Fuel molecular structure effect on soot mobility size in premixed C6 hydrocarbon flames

Soot formation in premixed laminar flames is examined for a canonical set of burning C6 hydrocarbon fuels. Particle mobility size and flame temperature measurements are complemented by structure calculations using detailed chemistry. Specifically, the evolution soot particle distribution (PSDF) compared n-hexane, n-hexene, 2-methylpentane, cyclohexane benzene at carbon-to-oxygen ratio 0.69 maximum 1800 K. Under this constraint, overall sooting process comparable as evidenced similar time resolved bimodal PSDF. However, first inception particles persistence nucleation-sized with depend upon parent fuel. For given conditions, fastest onset observed PSDF also shows that disappear sooner flames. Flame computations incorporating chemistry show clear connection between early fuel specific routes to PAH predicted pre-flame region These observations illustrate impact alkane, alkene, cycloalkane aromatic on Analysis morphology atomic force microscopy indicates most composed aggregates. Simple aggregate diameter analysis spherical assumption taken interpret does not number density result but inferred volume fraction aggregates deviates up an order magnitude depending assumptions adopted.