“…These approaches can be broadly categorized into two classes, namely, flamelets and non-flamelets or geometrical and statistical (Gicquel et al, 2012). The geometrical category of flamelets includes thickened flame (Colin et al, 2000;De and Acharya, 2009), flame surface density or flame-wrinkling (see, for example, Boger et al 1998;Chakraborty and Cant 2007;Chakraborty and Klein 2008;Gubba et al, 2012;Hawkes and Cant 2001;Knikker et al, 2004;Wang et al, 2012), and level-set or G equation (Moureau et al, 2008;Pitsch, 2005). The statistical category of flamelets includes approaches, such as EBU (eddy-break-up model), algebraic closure involving scalar dissipation rate (Butz et al, 2015;Dunstan et al, 2013;Gao et al, 2014;Langella et al, 2015;Ma et al, 2014), and presumed probability density function (PDF) methodology with laminar flamelets.…”