Краткое описание

LES models for subgrid scalar dissipation are tested a priori using experimental data from an axisymmetric, turbulent, co-flowing jet. The models tested include: a gradient-based model, which is based on a local equilibrium assumption, a model that assumes proportionality between mechanical and scalar time scales, and a dynamic structure model based on scale-similarity ideas. Of primary interest is the structural accuracy of the models, which can be assessed by computing a correlation coefficient between exact and modeled terms. We also examine some of the fundamental assumptions underlying the models. Results suggest that assumptions of time-scale proportionality are more valid than those of local equilibrium.