Implementation of Stochastic Particle Diffusion Length (SPDL) Method to Reacting Jet Flow

The Stochastic Particle Diffusion Length (SPDL) model is a new micromixing model to close probability density function (pdf) models. SPDL was utilizing the stochastic particles movement for the mixing process with molecular diffusion length scale. This micromixing model aims to cause stochastic particles to interact so that, on average, pairs are separated by twice the (turbulent) diffusion length scale. A Modified Curl’s model is proposed for the mixing of the particles. Initial tests of the model for doubled-function initial conditions show that this model obeys the relaxation to Gaussian rule. Further tests are to be undertaken for more complex cases. The complete interparticle-distance pdf is re-evaluated for each pair to ensure that there is sufficient capacity to mix to meet the variance decay requirements. Preliminary tests show that this model obeys several fundamental properties required of micromixing models. The current work expands past studies of NO conversion in a mixing layer to include a study of the Sandia D Flame in preparation for the application to more complex combustion phenomena. Results compare favorably with experimental data and other models.

Keyword: stochastic particles diffusion length, micromixing, reacting jet flow

M.M.Noor