Judy Cooper
Ansys Employee
Hi Edwin:nThe Moss-Brookes soot mechanism is hard-coded to use C2H2 and benzene precursors. nOne solution may be to use the Hall extension to the Moss-Brookes model. TheHall mechanism may be more accurate for higher order hydrocarbons. It still uses the benzene precursor, but estimates the formation rates of two-ringed and three-ringed aromatics (C10H7 and C14H10), from acetylene (C2H2), benzene (C6H6). The formation rates of these aromatics are then used to estimate soot formation rates.nFor the Method of Moments, did you try the built-in HACA mechanism? nTable 14.5 from the link below:nhttps://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v202/en/flu_th/flu_th_sec_soot_theory.html?q=sootnsuggests that pyrene is supported as a precursor for HACA. Note that pyrene would have to be present in your chemistry mechanism as a specie for this to work, however.nnBest Regards,nJudyn