MODELING MULTIPLE REACTIVE SCALAR MIXING WITH THE GENERALIZED IEM MODEL

An outstanding feature of the amplitude mapping closure is its ability to relax an arbitrary initial probability density function (PDF) to a Gaussian PDF asymptotically. Due to the difficulties in computing eit her the analytical or numerical solution, the mapping closure has neve r been applied to multiple scalars with finite reaction rates. In this work, the generalized IEM (GIEM) model is combined with the mapping c losure to model the molecular mixing terms in the PDF balance equation . The GIEM model assumes a Linear relationship between the rates of ch ange of the reactive scalars and an inert scalar (shadow scalar) durin g the mixing step. By applying the mapping closure for binary mixing t o the shadow scalar, the GIEM model yields excellent agreement for bot h one- and two-step reactions with DNS data, the conditional moment cl osure (CMC) and reaction-diffusion in a random lamellar system for a w ide range of initial volume ratios and reaction rates. (C) 1995 Americ an Institute of Physics.