wcao
Ansys Employee
Hello,nThe calculation of Y* is through time integration over the time scale tau* via either a stiff chemistry solver of chemkin CFD solver. Basically they are just ODE solvers that integrate the species mass fractions via the reaction rate calculated by Arrhenius law with temporary mass fractions. If you are referring to Magnussen for the original paper, most of the formula in it is assuming fast chemistry so that it might not be a good start point. You can refer to the article below, which has some derivation from Magnussen to the formula used by Fluent:nDe, A., Oldenhof, E., Sathiah, P. and Roekaerts, D., 2011. Numerical simulation of delft-jet-in-hot-coflow (djhc) flames using the eddy dissipation concept model for turbulence?chemistry interaction. Flow, Turbulence and Combustion, 87(4), pp.537-567. n